A stretchable wireless wearable bioelectronic system for multiplexed monitoring and combination treatment of infected chronic wounds

Smart bandages for wound monitoring and treatment

Wound management plays a crucial role in nursing care as it facilitates effective wound healing and prevents infections. To overcome limitations associated with traditional treatment methods, various smart bandages have been developed. The monitoring of wound parameters and the implementation of targeted treatments are crucial aspects of smart bandage development. Smart bandages, as cutting-edge flexible wearable medical devices, integrate various sensing technologies, providing new insights for dynamic monitoring and personalized treatment of chronic wounds. This paper systematically summarizes the applications and developments of smart bandages in monitoring wound environmental parameters, focusing on two major detection methods: colorimetric sensing and electrochemical sensing. Colorimetric sensors typically rely on color changes induced by physiological parameters, which can not only be identified by the naked eye but also combined with image recognition algorithms for physiological parameter detection. Electrochemical sensors, on the other hand, modify electrodes with specific enzymes and detect physiological parameters through the electrical signals generated by redox reactions. In addition to sensing, this paper further explores the integrated application of three smart therapeutic strategies in smart bandages, including promoting cell proliferation and angiogenesis through electrical stimulation, achieving controlled drug release via responsive materials, and utilizing photothermal materials for efficient antibacterial treatment of wounds. Finally, the paper delves into the challenges these bandages face in system integration and clinical translation, and discusses their potential in personalized wound care.

Combined treatment strategy of hydrogel dressing and physiotherapy for rapid wound healing

Wound care for open wounds is essential for reducing pain, protecting open wounds, speeding up the healing process and avoiding scar formation. Among the various three-dimensional (3D) carrier biomaterials such as films, sponges, and hydrogels, hydrogels are chemically and physically most similar to the natural extracellular matrix (ECM). Meanwhile, hydrogels are also common 3D carriers that can be efficiently loaded with drugs or cells. In addition, it forms a protective barrier on the wound surface to prevent secondary external infections and has the effect of directing skin cell expansion, tissue infiltration, and wound closure. However, the role of functional drugs in wound healing also faces a number of issues such as resistance, dosage, activity, and stability; therefore, a richer array of therapies is needed for wound repair and other areas of development. Physiotherapy, also known as nonpharmacological therapy, is a commonly used clinical treatment. Recently, more and more physiotherapy have been used for wound repair due to their high efficiency and low irritation. In recent reports, many researchers have tended to use hydrogel dressings in combination with physiotherapy, and this combination therapy is beneficial because it can both protect the wound microenvironment and accelerates wound healing. Therefore, this paper reviews the combined use of hydrogel dressings and physiotherapy in wound healing. We present the characteristics of hydrogel and physiotherapy and focus on the progress and problems of these two combined therapies in recent years.

A recent review on smart sensor-integrated wound dressings: Real-time monitoring and on-demand therapeutic delivery

Wound management is a critical aspect of healthcare, necessitating continuous monitoring and timely interventions to ensure optimal healing outcomes. In recent years, the integration of sensor technology into wound dressings has emerged as a transformative approach, enabling real-time monitoring of healing parameters and facilitating on-demand treatment delivery. Sensor-based wound dressings leverage various sensing modalities, including temperature, pH, moisture, oxygen, and other biochemical markers, to provide comprehensive insights into the wound microenvironment. These dressings are equipped with miniaturized sensors capable of transmitting the data wirelessly, facilitating remote monitoring and timely interventions. Moreover, some advanced dressings incorporate responsive drug delivery systems, enabling the on-demand release of therapeutics based on real-time sensor feedback. Additionally, the incorporation of on-demand treatment mechanisms allows targeted delivery of therapeutics based on the specific needs of the wound, further enhancing the efficacy of the healing process. This comprehensive approach improves patient outcomes by promoting faster and more effective wound healing and reducing the burden through streamlined monitoring and treatment protocols. This paper presents an overview of recent advancements in sensor technology applied to wound healing, focusing on their role in monitoring wound parameters and delivering targeted therapy. These sensors leverage temperature, pH, and glucose sensing modalities to provide comprehensive insights into the healing process.

Molecular-Level Strategy from Bottom-Up to Acquire High-Efficiency Antimicrobial Peptides

The escalating threat of multidrug-resistant pathogens necessitates efficient antimicrobial development, in which antimicrobial peptides (AMPs) have been extensively studied due to their broad-spectrum antibiotic activity. Combining sum frequency generation and molecular dynamics simulation, we rationally designed AMPs by identifying two structural principles. Simply increasing the number of basic amino acids does not reliably improve antimicrobial efficacy; terminal (N' and C') phenylalanine residues can enhance AMP's membrane interfacial activity via the hydrophobic effect. After two rounds of sequence optimization, among the derivatives we designed, an artificial AMP named GF demonstrated superior membrane binding (especially insertion) and spatial conformation stability. In vitro and in vivo evaluations revealed GF's potential broad-spectrum efficacy against common bacteria and drug-resistant bacteria. Notably, GF exhibited enhanced antimicrobial potency over conventional antibiotics at lower concentrations. Our study established a bottom-up (mechanism-driven) design framework and provided a template for developing precision antimicrobials against resistant infections.

Electrochemically Active Materials for Tissue-Interfaced Soft Biochemical Sensing

Tissue-interfaced soft biochemical sensing represents a crucial approach to personalized healthcare by employing electrochemically active materials to monitor biochemical signals at the tissue interface in real time, either noninvasively or through implantation. These soft biochemical sensors can be integrated with various biological tissues, such as neural, gastrointestinal, ocular, cardiac, skin, muscle, and bone, adapting to their unique mechanical and biochemical environments. Sensors employing materials like conductive polymers, composites, metals, metal oxides, and carbon-based nanomaterials have demonstrated capabilities in applications, such as continuous glucose monitoring, neural activity mapping, and real-time metabolite detection, enhancing diagnostics and treatment monitoring across a range of medical fields. Next-generation tissue-interfaced biosensors that enable multimodal and multiplexed measurement of biochemical markers and physiological parameters could be transformative for personalized medicine, allowing for high-resolution, time-resolved historical monitoring of an individual's health status. In this review, we summarize current trends in the field to provide insights into the challenges and future trajectory of tissue-interfaced soft biochemical sensors, highlighting their potential to revolutionize personalized medicine and improve patient outcomes.

NIR-Induced Power-Effective Smart Bandage for Wound Infection Monitoring and Accelerated Healing

An advanced bandage integrating sensing and therapeutic components for effective physiological monitoring and treatment presents promising potential for chronic wound healing. However, functional components in most bandages are integrated by wires, limiting the wearer's comfort of a soft-hard interface. Herein, a biocompatible smart flexible bandage, containing a reduced graphene oxide/polyacrylamide hydrogel (rGO/PAM Gel) therapeutic dressing and Au/rGO modified biosensor, has been designed. Owing to the photothermal capability of rGO/PAM Gel, the local temperature of the bandage significantly increased under NIR irradiation. High temperature accelerates infected wound healing by killing bacteria, while the bandage sensors enhance biomarker detection. Enriched target molecules and enhanced photo-electrocatalytic activity acquire high sensing performance. Moreover, in situ animal studies demonstrate that a smart wearable bandage could effectively monitor wound exudate biomarkers (i.e., uric acid) and accelerate healing with maximum light energy efficiency. This work provides a power-efficient approach to facilitate the immediate clinical intervention of wound care management.

Parallel assembly of dual-electrochemical cell: a novel approach for simultaneous multiplexed sensing analysis

In the field of biosensing and chemical sensing, there is a growing demand for multiplexed detection and quantification of multiple targets within complex matrices. In electrochemical sensing, simultaneous multiplexed analysis is typically performed with multiple electrodes connected to a multichannel potentiostat. An alternative strategy involves using a single electrode capable of discriminating and detecting several analytes in a single measurement, which is, however, unfortunately limited to a selective group of molecules. Herein, we report a novel electrochemical method based on the parallel assembly of a dual-electrochemical cell (PADEC), which enables the simultaneous detection and quantification of solvent-incompatible analytes, prepared separately in two distinct electrochemical cells, using a single-channel potentiostat-thus achieving multichannel-like performance. This approach relies on connecting two electrochemical cells in parallel, allowing the concurrent measurement of distinct electrochemical responses from analytes that otherwise could not be simultaneously determined  due to solvent incompatibility. As a proof of concept, the water-soluble vitamin C, and the lipid-soluble vitamin D3 were simultaneously determined, each in its respective optimized medium. The PADEC approach demonstrated performance comparable to individual detection methods, achieving limits of detection of 27 μM for vitamin C and 32 μM for vitamin D3 over a linear range of 20-400 μM. This strategy establishes a new approach for simultaneous, multiplexed electrochemical determination  of analytes in different media. Moreover, this innovation may extend applications in electrochemistry beyond (bio)sensing to include areas such as electrocatalysis, energy and corrosion, potentially reducing dependence on multichannel potentiostats.

Transforming Healthcare: Intelligent Wearable Sensors Empowered by Smart Materials and Artificial Intelligence

Intelligent wearable sensors, empowered by machine learning and innovative smart materials, enable rapid, accurate disease diagnosis, personalized therapy, and continuous health monitoring without disrupting daily life. This integration facilitates a shift from traditional, hospital-centered healthcare to a more decentralized, patient-centric model, where wearable sensors can collect real-time physiological data, provide deep analysis of these data streams, and generate actionable insights for point-of-care precise diagnostics and personalized therapy. Despite rapid advancements in smart materials, machine learning, and wearable sensing technologies, there is a lack of comprehensive reviews that systematically examine the intersection of these fields. This review addresses this gap, providing a critical analysis of wearable sensing technologies empowered by smart advanced materials and artificial Intelligence. The state-of-the-art smart materials-including self-healing, metamaterials, and responsive materials-that enhance sensor functionality are first examined. Advanced machine learning methodologies integrated into wearable devices are discussed, and their role in biomedical applications is highlighted. The combined impact of wearable sensors, empowered by smart materials and machine learning, and their applications in intelligent diagnostics and therapeutics are also examined. Finally, existing challenges, including technical and compliance issues, information security concerns, and regulatory considerations are addressed, and future directions for advancing intelligent healthcare are proposed.

Flexible Optoelectronic Hybrid Microfiber Long-period Grating Multimodal Sensor

Flexible wearable biosensors have emerged as a promising tool for tracking dynamic glycemic profiles of human body in diabetes management. However, it remains a challenge to balance the shrunken device space and multiple redundant sensing arrays for further advancement in miniaturization of multimodal sensors. Herein, this work proposes an entirely new optoelectronic hybrid multimodal optical fiber sensor which is composed of laser patterning of polydimethylsiloxane (PDMS) to form laser-induced graphene (LIG) as the interdigital electrodes, and a long period grating (LPG) prepared from an optical microfiber encapsulated into the PDMS modulated by periodical structure of LIG electrodes. This operation can simultaneously integrate two heterogeneous sensing mechanisms, optical and electrical, into a single sensor in a compact manner. Combining the LIG electrode with conductive hydrogel, a flexible glucose biosensor based on electrical mechanism is constructed by loading glucose oxidase into the hydrogel. Meanwhile, the microfiber LPG can also be served as a spectroscopically available sensor for biomechanical monitoring. Optical and electrical sensors can work simultaneously but independently of each other, particularly in the scene of wound healing for rat model and movement for human exercise. This platform represents a pivotal step toward multifunctional sensors that enable measurements of biomechanical information and glucose.

Recent Progress of Soft and Bioactive Materials in Flexible Bioelectronics

Materials that establish functional, stable interfaces to targeted tissues for long-term monitoring/stimulation equipped with diagnostic/therapeutic capabilities represent breakthroughs in biomedical research and clinical medicine. A fundamental challenge is the mechanical and chemical mismatch between tissues and implants that ultimately results in device failure for corrosion by biofluids and associated foreign body response. Of particular interest is in the development of bioactive materials at the level of chemistry and mechanics for high-performance, minimally invasive function, simultaneously with tissue-like compliance and in vivo biocompatibility. This review summarizes the most recent progress for these purposes, with an emphasis on material properties such as foreign body response, on integration schemes with biological tissues, and on their use as bioelectronic platforms. The article begins with an overview of emerging classes of material platforms for bio-integration with proven utility in live animal models, as high performance and stable interfaces with different form factors. Subsequent sections review various classes of flexible, soft tissue-like materials, ranging from self-healing hydrogel/elastomer to bio-adhesive composites and to bioactive materials. Additional discussions highlight examples of active bioelectronic systems that support electrophysiological mapping, stimulation, and drug delivery as treatments of related diseases, at spatiotemporal resolutions that span from the cellular level to organ-scale dimension. Envisioned applications involve advanced implants for brain, cardiac, and other organ systems, with capabilities of bioactive materials that offer stability for human subjects and live animal models. Results will inspire continuing advancements in functions and benign interfaces to biological systems, thus yielding therapy and diagnostics for human healthcare.

A Fully Integrated Wearable Biomimetic Microfluidic Wound Tracker for In Situ Dynamic Monitoring of Wound Exudate Oxygen

Wearable wound exudate sensors hold great promise for providing dynamic measurements of valuable biomarkers. However, no existing sensors are able to achieve the fully integrated, skin-on, and dynamic detection of raw wound exudate oxygen (O2), which is closely related to wound conditions and also essential for wound healing. Here, we report a fully integrated wearable biomimetic microfluidic wound tracker, capable of skin-on biomimetic microfluidic wound exudate sampling, dynamic monitoring of wound exudate O2 in addition to wound exudate uric acid, lactate, pH, and temperature, and wireless control through the seamless integration of specially designed microfluidic, sensing, and electronic modules. We test the performance of the device in both bacterium-inoculated and uninoculated wounds using mouse models. We further assess its potential for wound management in the healing process of infected diabetic mouse wounds through controlled experiments related to local hyperbaric O2 treatment.

Electrical hydrogel: electrophysiological-based strategy for wound healing

Wound healing remains a significant challenge in clinical practice, driving ongoing exploration of innovative therapeutic approaches. In recent years, electrophysiological-based wound healing strategies have gained considerable attention. Specifically, electrical hydrogels combine the synergistic effects of electrical stimulation and hydrogel properties, offering a range of functional benefits for wound healing, including antibacterial activity, real-time wound monitoring, controlled drug release, and electrical treatment. Despite significant progress made in electrical hydrogel research for wound healing, there is a lack of comprehensive, systematic reviews summarizing this field. In this review, we survey the latest advancements in electrical hydrogel technology. After analyzing the mechanisms of electrical stimulation in promoting wound healing, we establish a novel classification framework for electrical hydrogels based on their operational principles. The review further provides an in-depth evaluation of the therapeutic efficacy of these hydrogels in various types of wounds. Finally, we propose future directions and challenges for the development of electrical hydrogels for wound healing.

A microfluidic wearable device for wound exudate management and analysis in human chronic wounds

Chronic wounds are a major global health challenge associated with substantial economic burden and a negative impact on patient quality of life. Real-time analysis of biomarkers like reactive oxygen and nitrogen species could guide treatment, but existing systems lack the capacity required for continuous monitoring. Wound exudate is secreted slowly and has a complex composition, making efficient fluid collection and real-time analysis challenging. To address these issues, we introduce iCares, a wearable device for wound exudate management and continuous in situ analysis of wound biomarkers. iCares contains a flexible nanoengineered sensor array that measures reactive species such as NO, H2O2, and O2, along with pH and temperature, providing multiparameter data to inform wound status. The device features pump-free triad microfluidic modules with a superhydrophobic-superhydrophilic Janus membrane, bioinspired wedge channels, and three-dimensional graded micropillars for efficient unidirectional exudate collection, transport, and refreshing. The sensors demonstrated a consistent response and analyte selectivity in vitro and in wound exudate. iCares was designed for rapid scalable manufacturing through advanced printing and laser patterning. Wireless connectivity supported long-term continuous monitoring in wounds. The iCares system real-time monitoring was tested in a murine model of diabetic skin wound during infection and antimicrobial treatment. Clinical wound evaluation was conducted in 20 patients with chronic wounds and in two patients before and after surgery. A machine learning analysis of the multiplexed data successfully classified wounds and healing times, indicating that wound exudate analysis by iCares could offer insight into chronic wound status to aid in treatment decisions.

An Integrated Janus Bioelectronic Bandage for Unidirectional Pumping and Monitoring of Wound Exudate

Single-functional wound dressings provide limited therapeutic benefits for chronic wound healing. Effective care for chronic wounds requires a multifunction that integrates exudate management, therapeutic treatment, and continuous monitoring. Here, we introduce an integrated Janus bioelectronic wound care bandage designed to achieve self-pumping exudate management via an electrospinning Janus dressing with opposite wettability, antibacterial properties through silver nanoparticles (AgNPs), and the monitoring of multiplex biomarkers in wounds via electrochemical sensors positioned on the drainage side. The limits of detection (LOD) of sensors are 0.15 mM for glucose, 6.85 μM for UA, and 60.76 mV/decade for pH (4-8), respectively. We demonstrated in mice full-thickness wound models that this bandage effectively promoted wound healing, achieving a wound closure rate of 90.35% on day 14, and monitored the dynamic changes of three biomarkers within wounds in situ over a period of 3 days.

Electrochemical pH Sensor Incorporated Wearables for State-of-the-Art Wound Care

Nonhealing chronic wounds pose severe physiological and psychological distress to patients, making them a significant concern for global public health. Effective wound management strategies assisted by smart wearable pH monitoring have the potential to substantially alleviate both social and economic burdens. The pH of the wound exudate serves as a valuable indicator for predicting infections and assessing the healing status of wounds. This review comprehensively summarizes fundamental aspects related to wound pH, with a particular emphasis on the relationships between pH and healing status, infections, and other biochemical parameters that are crucial for wound health. It systematically discusses advancements in electrochemical pH sensors specifically designed for wearable devices, emphasizing their core performance in the care of chronic wounds. Additionally, the review outlines the challenges faced by this field and suggests future directions for research and development.

Advances in wearable electronics for monitoring human organs: Bridging external and internal health assessments

Devices used for diagnosing disease are often large, expensive, and require operation by trained professionals, which can result in delayed diagnosis and missed opportunities for timely treatment. However, wearable devices are being recognized as a new approach to overcoming these difficulties, as they are small, affordable, and easy to use. Recent advancements in wearable technology have made monitoring information possible from the surface of organs like the skin and eyes, enabling accurate diagnosis of the user's internal status. In this review, we categorize the body's organs into external (e.g., eyes, oral cavity, neck, and skin) and internal (e.g., heart, brain, lung, stomach, and bladder) organ systems and introduce recent developments in the materials and designs of wearable electronics, including electrochemical and electrophysiological sensors applied to each organ system. Further, we explore recent innovations in wearable electronics for monitoring of deep internal organs, such as the heart, brain, and nervous system, using ultrasound, electrical impedance tomography, and temporal interference stimulation. The review also addresses the current challenges in wearable technology and explores future directions to enhance the effectiveness and applicability of these devices in medical diagnostics. This paper establishes a framework for correlating the design and functionality of wearable electronics with the physiological characteristics and requirements of various organ systems.

Biomaterials for reliable wearable health monitoring: Applications in skin and eye integration

Recent advancements in biomaterials have significantly impacted wearable health monitoring, creating opportunities for personalized and non-invasive health assessments. These developments address the growing demand for customized healthcare solutions. Durability is a critical factor for biomaterials in wearable applications, as they must withstand diverse wearing conditions effectively. Therefore, there is a heightened focus on developing biomaterials that maintain robust and stable functionalities, essential for advancing wearable sensing technologies. This review examines the biomaterials used in wearable sensors, specifically those interfaced with human skin and eyes, highlighting essential strategies for achieving long-lasting and stable performance. We specifically discuss three main categories of biomaterials-hydrogels, fibers, and hybrid materials-each offering distinct properties ideal for use in durable wearable health monitoring systems. Moreover, we delve into the latest advancements in biomaterial-based sensors, which hold the potential to facilitate early disease detection, preventative interventions, and tailored healthcare approaches. We also address ongoing challenges and suggest future directions for research on material-based wearable sensors to encourage continuous innovation in this dynamic field.

Autonomous, Moisture-Driven Flexible Electrogenerative Dressing for Enhanced Wound Healing

Electrotherapy has shown considerable potential in treating chronic wounds, but conventional approaches relying on bulky external power supplies and mechanical force are limited in their clinical utility. This study introduces an autonomous, moisture-driven flexible electrogenerative dressing (AMFED) that overcomes these limitations. The AMFED integrates a moist-electric generator (MEG), an antibacterial hydrogel dressing, and concentric molybdenum (Mo) electrodes to provide a self-sustaining electrical supply and potent antibacterial activity against Staphylococcus aureus and Escherichia coli. The MEG harnesses chemical energy from moisture to produce a stable direct current of 0.61 V without external input, delivering this therapeutic electrical stimulation to the wound site through the Mo electrodes. The AMFED facilitates macrophage polarization toward reparative M2 phenotype and regulates inflammatory cytokines. Moreover, in vivo studies suggest that the AMFED group significantly enhances chronic wound healing, with an approximate 41% acceleration compared to the control group. Using a diabetic mouse wound model, the AMFED demonstrates its effectiveness in promoting nerve regulation, epithelial migration, and vasculogenesis. These findings present a novel and efficient platform for accelerating chronic wound healing.

Implantable wireless suture sensor for in situ tendon and ligament strain monitoring

Tendon and ligament ruptures are prevalent, and severe sports injuries require surgical repair. In clinical practice, monitoring of tissue strain is critical to alert severe postoperative complications such as graft reinjury and loosening. Here, we present a sensor system that integrates a strain sensor and communication coil onto surgical silk sutures, enabling in situ monitoring and wireless readout of tissue strains via surgical implantation. The flexible sensor shows excellent adaptability to soft tissues, providing a strain monitoring range of 0 to 10% with a minimum detection threshold of 0.25% and maintaining stability more than 300,000 stretching cycles. The wireless sensor could be integrated with complex structures in surgical scenarios involving lateral collateral ligament injury and anterior cruciate ligament reconstruction, enabling distinct responses to graft stretching, reinjury, and loosening. Animal experiments demonstrate that the sensor can acquire real-time, clinical-grade strain data while exhibiting high biocompatibility. The sensor system shows considerable potential in evaluating preclinical implant performance and monitoring implant-related surgical complications.

Bioinspired Intelligent Electronic Skin for Medicine and Healthcare

Intelligent electronic skin aims to mimic, enhance, and even surpass the functions of biological skin, enabling artificial systems to sense environmental stimuli and interact more naturally with humans. In healthcare, intelligent electronic skin is revolutionizing diagnostics and personalized medicine by detecting early signs of diseases and programming exogenous stimuli for timely intervention and on-demand treatment. This review discusses latest progress in bioinspired intelligent electronic skin and its application in medicine and healthcare. First, strategies for the development of intelligent electronic skin to simulate or even surpass human skin are discussed, focusing on its basic characteristics, as well as sensing and regulating functions. Then, the applications of electronic skin in health monitoring and wearable therapies are discussed, illustrating its potential to provide early warning and on-demand treatment. Finally, the significance of electronic skin in bridging the gap between electronic and biological systems is emphasized and the challenges and future perspectives of intelligent electronic skin are summarized.

Fully Printed Flexible Polystyrene/Graphite-Based Temperature Sensor with Excellent Properties for Potential Smart Applications

This study presents an innovative temperature sensor based on a thermistor nanocomposite of graphite (Gt) and polystyrene (PS). The sensor exhibited notable thermal stability and film integrity, offering two distinct linear response regions within the tested temperature range of -10 to 60 °C. It demonstrated a sensitivity of 0.125% °C-1 between -10 and 10 °C, followed by another linear response with a sensitivity of 0.41% °C-1 from 20 to 60 °C. Furthermore, it exhibited a response/recovery time of 0.97/1.3 min at a heating/cooling rate of 60 °C min-1. The sensor maintained minimal baseline drift even when subjected to varying humidity levels. We assessed its mechanical flexibility and stability for hundreds of bending cycles at a bending angle of 30°, adapting to dynamic environmental conditions. The sensor's thermomechanical test (response to mechanical stress under temperature fluctuations) underscored its adaptability over a temperature range of -10 to 60 °C. Notably, it displayed excellent chemical stability, maintaining consistent performance when subjected to harsh environmental conditions like exposure to corrosive gases and prolonged immersion in tap water. Real-world tests demonstrated its practical utility, including precise temperature measurements in solid objects and breath temperature monitoring. These findings suggest promising applications in healthcare, environmental monitoring, and various IoT applications.

Emerging Wearable Acoustic Sensing Technologies

Sound signals not only serve as the primary communication medium but also find application in fields such as medical diagnosis and fault detection. With public healthcare resources increasingly under pressure, and challenges faced by disabled individuals on a daily basis, solutions that facilitate low-cost private healthcare hold considerable promise. Acoustic methods have been widely studied because of their lower technical complexity compared to other medical solutions, as well as the high safety threshold of the human body to acoustic energy. Furthermore, with the recent development of artificial intelligence technology applied to speech recognition, speech recognition devices, and systems capable of assisting disabled individuals in interacting with scenes are constantly being updated. This review meticulously summarizes the sensing mechanisms, materials, structural design, and multidisciplinary applications of wearable acoustic devices applied to human health and human-computer interaction. Further, the advantages and disadvantages of the different approaches used in flexible acoustic devices in various fields are examined. Finally, the current challenges and a roadmap for future research are analyzed based on existing research progress to achieve more comprehensive and personalized healthcare.

Triboelectric Bending Sensors for AI-Enabled Sign Language Recognition

Human-machine interfaces and wearable electronics, as fundamentals to achieve human-machine interactions, are becoming increasingly essential in the era of the Internet of Things. However, contemporary wearable sensors based on resistive and capacitive mechanisms demand an external power, impeding them from extensive and diverse deployment. Herein, a smart wearable system is developed encompassing five arch-structured self-powered triboelectric sensors, a five-channel data acquisition unit to collect finger bending signals, and an artificial intelligence (AI) methodology, specifically a long short-term memory (LSTM) network, to recognize signal patterns. A slider-crank mechanism that precisely controls the bending angle is designed to quantitively assess the sensor's performance. Thirty signal patterns of sign language of each letter are collected and analyzed after the environment noise and cross-talks among different channels are reduced and removed, respectively, by leveraging low pass filters. Two LSTM models are trained using different training sets, and four indexes are introduced to evaluate their performance, achieving a recognition accuracy of 96.15%. This work demonstrates a novel integration of triboelectric sensors with AI for sign language recognition, paving a new application avenue of triboelectric sensors in wearable electronics.

A Smart Semi-Implantable Device Integrating Microchannel-Enhanced Sampling and Multiplex Biochemical Testing for Deep Wound Monitoring and Pathogen Identification

Monitoring deep wounds is challenging but necessary for high-quality medical treatment. Current methodologies for deep wound monitoring are typically limited to indirect clinical symptoms or costly non-real-time imaging diagnosis. Herein, a smart system is proposed that enables in situ monitoring of deep wounds' status through a semi-implantable device composed of 2 seamlessly connected functional components: 1) the well-designed, microchannel-structured sampling needles that efficiently and conveniently collect samples from deep wound anatomical locations, and 2) the multiplex biochemical testing compartment that facilitates the immediate and persistent detection of multiple biochemical indicators based on a color image processing software accessible to a conventional smartphone. With the 3 representative preclinical deep wound models, the study demonstrates the device's potential to monitor wound infection, inflammation, healing progress, and reduce inflammation when applied to deep skin injury, surgical implantation, and postoperative intestinal leakage. The device's capability to rapidly and accurately identify pathogenic bacteria is also demonstrated both in vitro and in vivo, potentially facilitating precise intervention in infected wounds. Coupled with the device's favorable biocompatibility and cost-effectiveness, this intelligent system emerges as a promising tool for safe and effective management of complicated deep wounds.

Modular Reconfigurable Approach Toward Noninvasive Wearable Body Net for Monitoring Sweat and Physiological Signals

In the realm of wearable technology, strategically placing sensors at various body locations enhances the detection of diverse physiological indicators crucial for remote medical care. However, current devices often focus on a single body part for specific physical parameters, which hinders the seamless integration of sensors across multiple body parts and necessitates redesign for new detection capabilities. Here, we propose a modular, reconfigurable circuit assembly method that can be adaptable for multiple body locations to construct the body net. By simply reassembling different child modules with the base module using flexible printed circuit board connectors, we can efficiently detect various parameters including sweat ion indicators, electrocardiogram signals, electromyography signals, motion data, heart rate, blood oxygen saturation, and skin temperature. These data can be transmitted to a mobile phone app via a Bluetooth Low Energy protocol for further evaluation. Comparative evaluations against established commercial devices substantiate the viability of our sensor technology. In addition, results from wearable body network detections using reconfigurable sensors across multiple body parts of volunteers also indicate promising application prospects, demonstrating the extensive potential for regular health monitoring and clinical applications.

Wireless matrix metalloproteinase-9 sensing by smart wound dressing with controlled antibacterial nanoparticles release toward chronic wound management

Chronic wounds cause serious health and economic burdens on patients and society. Herein, a wireless and flexible smart wound dressing was developed for matrix metalloproteinase-9 (MMP-9) monitoring and antimicrobial treatment toward chronic wound management. The highly sensitive radio frequency MMP-9 sensor was realized based on a bioresponsive hydrogel with the bioactive peptide sequences. Taking advantage of the flexible inductive-capacitive (LC) circuit and bioresponsive hydrogel, the wireless and wearable smart wound dressing offered an efficient strategy for in-situ wound analysis. Besides, the controlled release of silver nanoparticles (AgNPs) from the degradable hydrogel exhibited significant antimicrobial efficacy against typical bacteria in wound infection including Escherichia coli and Staphylococcus aureus. The analysis of MMP-9 in wound exudate from diabetic foot ulcer (DFU) patients demonstrated good accuracy cross-validated with gold-standard fluorescent measurements, providing great potential for personalized wound management.

Advancements in Passive Wireless Sensing Systems in Monitoring Harsh Environment and Healthcare Applications

Recent advancements in passive wireless sensor technology have significantly extended the application scope of sensing, particularly in challenging environments for monitoring industry and healthcare applications. These systems are equipped with battery-free operation, wireless connectivity, and are designed to be both miniaturized and lightweight. Such features enable the safe, real-time monitoring of industrial environments and support high-precision physiological measurements in confined internal body spaces and on wearable epidermal devices. Despite the exploration into diverse application environments, the development of a systematic and comprehensive research framework for system architecture remains elusive, which hampers further optimization of these systems. This review, therefore, begins with an examination of application scenarios, progresses to evaluate current system architectures, and discusses the function of each component-specifically, the passive sensor module, the wireless communication model, and the readout module-within the context of key implementations in target sensing systems. Furthermore, we present case studies that demonstrate the feasibility of proposed classified components for sensing scenarios, derived from this systematic approach. By outlining a research trajectory for the application of passive wireless systems in sensing technologies, this paper aims to establish a foundation for more advanced, user-friendly applications.

Large Scale Ultrafast Manufacturing of Wireless Soft Bioelectronics Enabled by Autonomous Robot Arm Printing Assisted by a Computer Vision-Enabled Guidance System for Personalized Wound Healing

A Customized wound patch for Advanced tissue Regeneration with Electric field (CARE), featuring an autonomous robot arm printing system guided by a computer vision-enabled guidance system for fast image recognition is introduced. CARE addresses the growing demand for flexible, stretchable, and wireless adhesive bioelectronics tailored for electrotherapy, which is suitable for rapid adaptation to individual patients and practical implementation in a comfortable design. The visual guidance system integrating a 6-axis robot arm enables scans from multiple angles to provide a 3D map of complex and curved wounds. The size of electrodes and the geometries of power-receiving coil are essential components of the CARE and are determined by a MATLAB simulation, ensuring efficient wireless power transfer. Three heterogeneous inks possessing different rheological behaviors can be extruded and printed sequentially on the flexible substrates, supporting fast manufacturing of large customized bioelectronic patches. CARE can stimulate wounds up to 10 mm in depth with an electric field strength of 88.8 mV mm-1. In vitro studies reveal the ability to accelerate cell migration by a factor of 1.6 and 1.9 for human dermal fibroblasts and human umbilical vein endothelial cells, respectively. This study highlights the potential of CARE as a clinical wound therapy method to accelerate healing.

Wearable Electrochemical Biosensors for Advanced Healthcare Monitoring

Recent advancements in wearable electrochemical biosensors have opened new avenues for on-body and continuous detection of biomarkers, enabling personalized, real-time, and preventive healthcare. While glucose monitoring has set a precedent for wearable biosensors, the field is rapidly expanding to include a wider range of analytes crucial for disease diagnosis, treatment, and management. In this review, recent key innovations are examined in the design and manufacturing underpinning these biosensing platforms including biorecognition elements, signal transduction methods, electrode and substrate materials, and fabrication techniques. The applications of these biosensors are then highlighted in detecting a variety of biochemical markers, such as small molecules, hormones, drugs, and macromolecules, in biofluids including interstitial fluid, sweat, wound exudate, saliva, and tears. Additionally, the review also covers recent advances in wearable electrochemical biosensing platforms, such as multi-sensory integration, closed-loop control, and power supply. Furthermore, the challenges associated with critical issues are discussed, such as biocompatibility, biofouling, and sensor degradation, and the opportunities in materials science, nanotechnology, and artificial intelligence to overcome these limitations.

Dual action electrochemical bandage operated by a programmable multimodal wearable potentiostat

We have developed electrochemical bandage (e-bandage) prototypes that generate the reactive oxygen species hypochlorous acid (HOCl) or hydrogen peroxide (H2O2) for potential use to treat biofilm-infected wounds in humans. We have shown that both e-bandage-generated HOCl and H2O2 kill biofilms in vitro and in infected wounds on mice, with the former being more active in vitro. The H2O2-generating e-bandage, more so than the HOCl-generating e-bandage, was associated with improved healing of infected wounds. Here, a strategy in which H2O2 and HOCl are alternately generated-for dual action-was explored. The goal was to develop a programmable multimodal wearable potentiostat [PMWP] that can generate HOCl or H2O2, as needed. An ultralow-power microcontroller unit was developed to manage operation of the PMWP. The system was operated with a 260-mAh capacity coin battery and weighed 4.6 g, making it suitable for future small animal experiments (and ultimately, potential evaluation in humans). As assessed using electrochemical parameters, the device functioned comparably to a commercial benchtop potentiostat. To confirm antimicrobial activity, PMWP-controlled e-bandages were tested in vitro against clinical isolates of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecium, and Candida auris. When programmed to deliver HOCl followed by H2O2, PMWP-controlled e-bandages exhibited activity against biofilms of all study isolates tested. Finally, we demonstrated the PMWP's usability in a murine wound infection model.

Ammonium Sensing Patch with Ultrawide Linear Range and Eliminated Interference for Universal Body Fluids Analysis

Ammonium level in body fluids serves as one of the critical biomarkers for healthcare, especially those relative to liver diseases. The continuous and real-time monitoring in both invasive and non-invasive manners is highly desired, while the ammonium concentrations vary largely in different body fluids. Besides, the sensing reliability based on ion-selective biosensors can be significantly interfered by potassium ions. To tackle these challenges, a flexible and biocompatible sensing patch for wireless ammonium level sensing was reported with an ultrawide linear range for universal body fluids including blood, tears, saliva, sweat and urine. The as-prepared biocompatible sensors deliver a reliable sensitivity of 58.7 mV decade-1 in the range of 1-100 mM and a desirable selectivity coefficient of 0.11 in the interference of potassium ions, attributed to the cross-calibration within the sensors array. The sensor's biocompatibility was validated by the cell growth on the sensor surface (> 80%), hemolysis rates (< 5%), negligible cellular inflammatory responses and weight changes of the mice with implanted sensors. Such biocompatible sensors with ultrawide linear range and desirable selectivity open up new possibility of highly compatible biomarker analysis via different body fluids in versatile approaches.

Flexible bioelectronic systems with large-scale temperature sensor arrays for monitoring and treatments of localized wound inflammation

Continuous monitoring and closed-loop therapy of soft wound tissues is of particular interest in biomedical research and clinical practices. An important focus is on the development of implantable bioelectronics that can measure time-dependent temperature distribution related to localized inflammation over large areas of wound and offer in situ treatment. Existing approaches such as thermometers/thermocouples provide limited spatial resolution, inapplicable to a wearable/implantable format. Here, we report a conformal, scalable device package that integrates a flexible amorphous silicon-based temperature sensor array and drug-loaded hydrogel for the healing process. This system can enable the spatial temperature mapping at submillimeter resolution and high sensitivity of 0.1 °C, for dynamically localizing the inflammation regions associated with temperature change, automatically followed with heat-triggered drug delivery from hydrogel triggered by wearable infrared light-emitting-diodes. We establish the operational principles experimentally and computationally and evaluate system functionalities with a wide range of targets including live animal models and human subjects. As an example of medical utility, this system can yield closed-loop monitoring/treatments by tracking of temperature distribution over wound areas of live rats, in designs that can be integrated with automated wireless control. These findings create broad utilities of these platforms for clinical diagnosis and advanced therapy for wound healthcare.

Applied body-fluid analysis by wearable devices

Wearable sensors are a recent paradigm in healthcare, enabling continuous, decentralized, and non- or minimally invasive monitoring of health and disease. Continuous measurements yield information-rich time series of physiological data that are holistic and clinically meaningful. Although most wearable sensors were initially restricted to biophysical measurements, the next generation of wearable devices is now emerging that enable biochemical monitoring of both small and large molecules in a variety of body fluids, such as sweat, breath, saliva, tears and interstitial fluid. Rapidly evolving data analysis and decision-making technologies through artificial intelligence has accelerated the application of wearables around the world. Although recent pilot trials have demonstrated the clinical applicability of these wearable devices, their widespread adoption will require large-scale validation across various conditions, ethical consideration and sociocultural acceptance. Successful translation of wearable devices from laboratory prototypes into clinical tools will further require a comprehensive transitional environment involving all stakeholders. The wearable device platforms must gain acceptance among different user groups, add clinical value for various medical indications, be eligible for reimbursements and contribute to public health initiatives. In this Perspective, we review state-of-the-art wearable devices for body-fluid analysis and their translation into clinical applications, and provide insight into their clinical purpose.

Beyond Flexible: Unveiling the Next Era of Flexible Electronic Systems

Flexible electronics are integral in numerous domains such as wearables, healthcare, physiological monitoring, human-machine interface, and environmental sensing, owing to their inherent flexibility, stretchability, lightweight construction, and low profile. These systems seamlessly conform to curvilinear surfaces, including skin, organs, plants, robots, and marine species, facilitating optimal contact. This capability enables flexible electronic systems to enhance or even supplant the utilization of cumbersome instrumentation across a broad range of monitoring and actuation tasks. Consequently, significant progress has been realized in the development of flexible electronic systems. This study begins by examining the key components of standalone flexible electronic systems-sensors, front-end circuitry, data management, power management and actuators. The next section explores different integration strategies for flexible electronic systems as well as their recent advancements. Flexible hybrid electronics, which is currently the most widely used strategy, is first reviewed to assess their characteristics and applications. Subsequently, transformational electronics, which achieves compact and high-density system integration by leveraging heterogeneous integration of bare-die components, is highlighted as the next era of flexible electronic systems. Finally, the study concludes by suggesting future research directions and outlining critical considerations and challenges for developing and miniaturizing fully integrated standalone flexible electronic systems.

Nanomaterials for Flexible Neuromorphics

The quest to imbue machines with intelligence akin to that of humans, through the development of adaptable neuromorphic devices and the creation of artificial neural systems, has long stood as a pivotal goal in both scientific inquiry and industrial advancement. Recent advancements in flexible neuromorphic electronics primarily rely on nanomaterials and polymers owing to their inherent uniformity, superior mechanical and electrical capabilities, and versatile functionalities. However, this field is still in its nascent stage, necessitating continuous efforts in materials innovation and device/system design. Therefore, it is imperative to conduct an extensive and comprehensive analysis to summarize current progress. This review highlights the advancements and applications of flexible neuromorphics, involving inorganic nanomaterials (zero-/one-/two-dimensional, and heterostructure), carbon-based nanomaterials such as carbon nanotubes (CNTs) and graphene, and polymers. Additionally, a comprehensive comparison and summary of the structural compositions, design strategies, key performance, and significant applications of these devices are provided. Furthermore, the challenges and future directions pertaining to materials/devices/systems associated with flexible neuromorphics are also addressed. The aim of this review is to shed light on the rapidly growing field of flexible neuromorphics, attract experts from diverse disciplines (e.g., electronics, materials science, neurobiology), and foster further innovation for its accelerated development.

Multi-Electrode Extended Gate Field Effect Transistors Based on Laser-Induced Graphene for the Detection of Vitamin C and SARS-CoV-2

Despite the clinical data showing the importance of ascorbic acid (AA or vitamin C) in managing viral respiratory infections, biosensors for their simultaneous detection are lacking. To address this need, we developed a portable and wireless device for simultaneous detection of AA and SARS-CoV-2 virus by integrating commercial transistors with printed laser-induced graphene (LIG) as the extended gate. We studied the effect of laser printing pass number and showed that with two laser printing passes (2-pass LIG), the sensor sensitivity and limit of detection (LOD) for AA improved by a factor of 1.6 and 12.8, respectively. Using complementary characterization methods, we attribute the improved response to a balanced interplay of crystallinity, defect density, surface area, surface roughness, pore density and diameter, and mechanical integrity/stability. These factors enhance analyte transport, reduce noise/variability, and ensure consistent sensor performance, making 2-pass LIG the most effective material in this work. Our sensors exhibit promising performance for detecting AA with a selective response in the presence of common salivary interfering molecules, with sensitivity and LOD of 73.67 mV/dec and 54.04 nM in 1× phosphate buffered saline and 81.05 mV/dec and 78.34 nM in artificial saliva, respectively. We also showed that functionalization of the 2-pass LIG gate with S-protein antibody enables the detection of SARS-CoV-2 protein antigens with an ultralow LOD of 52 zg/mL─an improvement of more than 10-fold compared to 1-pass LIG─and 4 particles/mL for virion mimics with a selective response against influenza virus and multiple human coronavirus strains. With low signal drift/hysteresis and wireless capabilities, the developed device holds great potential for improving at-home monitoring and clinical decision-making.

Highly Elastic, Fatigue-Resistant, and Antifreezing MXene Functionalized Organohydrogels as Flexible Pressure Sensors for Human Motion Monitoring

Conductive organohydrogels-based flexible pressure sensors have gained considerable attention in health monitoring, artificial skin, and human-computer interaction due to their excellent biocompatibility, wearability, and versatility. However, hydrogels' unsatisfactory mechanical and unstable electrical properties hinder their comprehensive application. Herein, an elastic, fatigue-resistant, and antifreezing poly(vinyl alcohol) (PVA)/lipoic acid (LA) organohydrogel with a double-network structure and reversible cross-linking interactions has been designed, and MXene as a conductive filler is functionalized into organohydrogel to further enhance the diverse sensing performance of flexible pressure sensors. The as-fabricated MXene-based PVA/LA organohydrogels (PLBM) exhibit stable fatigue resistance for over 450 cycles under 40% compressive strain, excellent elasticity, antifreezing properties (<-20 °C), and degradability. Furthermore, the pressure sensors based on the PLBM organohydrogels show a fast response time (62 ms), high sensitivity (S = 0.0402 kPa-1), and excellent stability (over 1000 cycles). The exceptional performance enables the sensors to monitor human movements, such as joint flexion and throat swallowing. Moreover, the sensors integrating with the one-dimensional convolutional neural networks and the long-short-term memory networks deep learning algorithms have been developed to recognize letters with a 93.75% accuracy, representing enormous potential in monitoring human motion and human-computer interaction.

Integration of Functional Polymers and Biosensors to Enhance Wound Healing

Biosensors have led to breakthroughs in the treatment of chronic wounds. Since the discovery of the oxygen electrode by Clarke, biosensors have evolved into the design of smart bandages that dispense drugs to treat wounds in response to physiological factors, such as pH or glucose concentration, which indicate pathogenic tendencies. Aptamer-based biosensors have helped identify and characterize pathogenic bacteria in wounds that often form antibiotic-resistant biofilms. Several functional polymers have served as indispensable parts of the fabrication of these biosensors. Beginning with natural polymers such as alginate, chitosan, and silk-based fibroin, which are biodegradable and absorptive, advances have been made in formulating biocompatible synthetic polymers such as polyurethane and polyethylene glycol designed to reduce non-specific binding of proteins and cells, making biosensors less painful or cumbersome for patient use. Recently, polycaprolactone has been developed, which offers ductility and a large surface-area-to-volume ratio. There is still room for advances in the fabrication and use of biosensors for wound healing and in this review, the trend in developing biosensors from biomarker detection to smart dressings to the incorporation of machine learning in designing customized wound patches while making application easier is highlighted and can be used for a long time.

Conductive hydrogels: intelligent dressings for monitoring and healing chronic wounds

Conductive hydrogels (CHs) represent a burgeoning class of intelligent wound dressings, providing innovative strategies for chronic wound repair and monitoring. Notably, CHs excel in promoting cell migration and proliferation, exhibit powerful antibacterial and anti-inflammatory properties, and enhance collagen deposition and angiogenesis. These capabilities, combined with real-time monitoring functions, play a pivotal role in accelerating collagen synthesis, angiogenesis and continuous wound surveillance. This review delves into the preparation, mechanisms and applications of CHs in wound management, highlighting their diverse and significant advantages. It emphasizes the effectiveness of CHs in treating various chronic wounds, such as diabetic ulcers, infected wounds, temperature-related injuries and athletic joint wounds. Additionally, it explores the diverse applications of multifunctional intelligent CHs in advanced wound care technologies, encompassing self-powered dressings, electrically-triggered drug delivery, comprehensive diagnostics and therapeutics and scar-free healing. Furthermore, the review highlights the challenges to their broader implementation, explores the future of intelligent wound dressings and discusses the transformative role of CHs in chronic wound management, particularly in the context of the anticipated integration of artificial intelligence (AI). Additionally, this review underscores the challenges hindering the widespread adoption of CHs, delves into the prospects of intelligent wound dressings and elucidates the transformative impact of CHs in managing chronic wounds, especially with the forthcoming integration of AI. This integration promises to facilitate predictive analytics and tailor personalized treatment plans, thereby further refining the healing process and elevating patient satisfaction. Addressing these challenges and harnessing emerging technologies, we postulate, will establish CHs as a cornerstone in revolutionizing chronic wound care, significantly improving patient outcomes.

A Scoping Review of 'Smart' Dressings for Diagnosing Surgical Site Infection: A Focus on Arthroplasty

Early diagnosis and treatment of surgical wound infection can be challenging. This is especially relevant in the management of periprosthetic joint infection: early detection is key to success and reducing morbidity, mortality and resource use. 'Smart' dressings have been developed to detect parameters suggestive of infection. This scoping review investigates the current status of the field, limited to devices tested in animal models and/or humans, with a focus on their application to arthroplasty. The literature was searched using MEDLINE/PubMed and Embase databases from 2000 to 2023. Original articles assessing external sensing methods for the detection of wound infection in animal models or human participants were included. Sixteen articles were eligible. The results were broadly divided by sensing method: colorimetric, electrochemical and fluorescence/photothermal responses. Six of the devices detected more than one parameter (multimodal), while the rest were unimodal. The most common parameters examined were temperature and pH. Most 'smart' dressings focused on diagnosing infection in chronic wounds, and none were tested in humans with wound infections. There is limited late-stage research into using dressing sensors to diagnose wound infection in post-surgical patients. Future research should explore this to enable inpatient and remote outpatient monitoring of post-operative wounds to detect wound infection.

Fully Integrated Biosensing System for Dynamic Monitoring of Sweat Glucose and Real-Time pH Adjustment Based on 3D Graphene MXene Aerogel

The development of noninvasive glucose sensors capable of continuous monitoring without restricting user mobility is crucial, particularly for managing diabetes, which demands consistent and long-term observation. Traditional sensors often face challenges with accuracy and stability that curtail their practical applications. To address these issues, we have innovatively applied a three-dimensional porous aerogel composed of Ti3C2Tx MXene and reduced graphene oxide (MX-rGO) in electrochemical sensing. It significantly reduces the electron-transfer distance between the enzyme's redox center and the electrode surface while firmly anchoring the enzyme layer to effectively prevent any leakage. Another pivotal advancement in our study is the integration of the sensor with a real-time adaptive calibration mechanism tailored specifically for analyzing sweat glucose. This sensor not only measures glucose levels but also dynamically monitors and adjusts to pH fluctuations in sweat. Such capabilities ensure the precise delivery of physiological data during physical activities, providing strong support for personalized health management.

Recent Advances in Transparent Electrodes and Their Multimodal Sensing Applications

This review examines the recent advancements in transparent electrodes and their crucial role in multimodal sensing technologies. Transparent electrodes, notable for their optical transparency and electrical conductivity, are revolutionizing sensors by enabling the simultaneous detection of diverse physical, chemical, and biological signals. Materials like graphene, carbon nanotubes, and conductive polymers, which offer a balance between optical transparency, electrical conductivity, and mechanical flexibility, are at the forefront of this development. These electrodes are integral in various applications, from healthcare to solar cell technologies, enhancing sensor performance in complex environments. The paper addresses challenges in applying these electrodes, such as the need for mechanical flexibility, high optoelectronic performance, and biocompatibility. It explores new materials and innovative techniques to overcome these hurdles, aiming to broaden the capabilities of multimodal sensing devices. The review provides a comparative analysis of different transparent electrode materials, discussing their applications and the ongoing development of novel electrode systems for multimodal sensing. This exploration offers insights into future advancements in transparent electrodes, highlighting their transformative potential in bioelectronics and multimodal sensing technologies.

Zein-Coated Zn Metal Particles-Incorporated Nanofibers: A Potent Fibrous Platform for Loading and Release of Zn Ions for Wound Healing Application

Metal particles incorporated into polymer matrices in various forms and geometries are attractive material platforms for promoting wound healing and preventing infections. However, the fate of these metal particles and their degraded products in the tissue environment are still unknown, as both can produce cytotoxic effects and promote unwanted wound reactions. In this study, we develop biodegradable fibrous biomaterials embedded with metal particles that have an immune activation functions. Initially, biodegradable zinc (Zn) nanoparticles were modified with zein (G), a protein derived from corn. The zein-coated zinc particles (Z-G) were then embedded in polycaprolactone (P) fibers at different weight ratios to create fibrous biomaterials via electrospinning, which were subsequently analyzed for potential wound healing applications. We performed multimodal evaluations of the fibrous scaffolds, examining physicochemical properties such as fiber morphology, mechanical strength, hydrophilicity, degradation, and release of zinc ions (Zn2+), as well as biological properties, including in vitro cell culture studies. We provide evidence that the integration of 2.4 wt % of Z-G particles in polycaprolactone (PCL) nanofibrous scaffolds improved its physicochemical and biological functions. The in vitro cellular response of the scaffolds was evaluated using a series of cytotoxicity assays and immunocytochemistry analyses with three different cell types: mouse-derived fibroblast cell lines (NIH/3T3), human dermal fibroblasts (HDFn), and human umbilical vein endothelial cells (HUVECs). The composite fibrous scaffold exhibited robust activation and proliferation of NIH/3T3 and HDFn cells, along with a significant angiogenic potential in HUVECs. Immunocytochemistry confirmed elevated expression of vimentin and α-smooth muscle actin (α-SMA), suggesting that NIH/3T3 and Haden cells were highly differentiated into myofibroblasts. Additionally, the increased expression of CD31 and VE-cadherin in HUVECs suggests that the scaffold supports tube formation, thereby enhancing neovascularization and promoting an effective immune response. Overall, our findings demonstrate the regenerative potential of the self-enhanced Zn hemostatic bioscaffolds, which deliver both Zn2+ ions and zein proteins to nourish cells. This capability not only modulates cellular activities but also contributes to tissue repair and remodeling, making the scaffolds suitable for wound repair and various bioengineering applications.

Diving into Sweat: Advances, Challenges, and Future Directions in Wearable Sweat Sensing

Sweat analysis has advanced from diagnosing cystic fibrosis and testing for illicit drugs to noninvasive monitoring of health biomarkers. This article introduces the rapid development of wearable and flexible sweat sensors, highlighting key milestones and various sensing strategies for real-time monitoring of analytes. We discuss challenges such as developing high-performance nanomaterial-based biosensors, ensuring continuous sweat production and sampling, achieving high sweat/blood correlation, and biocompatibility. The potential of machine learning to enhance these sensors for personalized healthcare is presented, enabling real-time tracking and prediction of physiological changes and disease onset. Leveraging advancements in flexible electronics, nanomaterials, biosensing, and data analytics, wearable sweat biosensors promise to revolutionize disease management, prevention, and prediction, promoting healthier lifestyles and transforming medical practices globally.

A Fully Integrated Conformal Wearable Ultrasound Patch for Continuous Sonodynamic Therapy

Cancer treatment is a continuous process, that the current therapy cannot meet the requirement well, including radiotherapy and chemotherapy. Wearable ultrasound device has the potential for continuous sonodynamic therapy due to its portability. However, the miniaturization of ultrasonic probe, system integration of device, and the strategy of continuous treatment are still urgent issues to be addressed. Herein, a portable wearable antitumor system is introduced, which utilizes a custom-developed multiplexed ultrasonic patch array (CWUS Patch) to accurately focus ultrasound on the lesion site and controllably stimulate sonosensitizer to produce a large amount of toxic reactive oxygen species (ROS). The system enables dynamic control of the ultrasound patches and allows real-time adjustments to optimize their performance in various applications, providing greater flexibility and precision in healthcare technology. Furthermore, the excellent penetration property of ultrasound into tumor tissues that induce synchronous apoptosis of tumor cells from the inside out is verified through a mouse model of breast cancer. This fully integrated conformal wearable ultrasound system provides a promising approach to noninvasively, continuously, and efficiently treat deep tumors.

Wearable dual-drug controlled release patch for psoriasis treatment

Wearable drug delivery systems (DDS) have made significant advancements in the field of precision medicine, offering precise regulation of drug dosage, location, and timing. The performance qualities that wearable DDS has always strived for are simplicity, efficiency, and intelligence. This paper proposes a wearable dual-drug synergistic release patch. The patch is powered by a built-in magnesium battery and utilizes a hydrogel containing viologen-based hyperbranched polyamidoamine as both a cathode material and an integrated drug reservoir. This design allows for the simultaneous release of both dexamethasone and tannic acid, overcoming the limitations of monotherapy and ensuring effective synergy for on-demand therapy. In a mouse model with praziquimod-induced psoriasis, the patch demonstrated therapeutic efficacy at a low voltage. The inflammatory skin returned to normal after 5 days with the on-demand release of dual drugs. This work provides a promising treatment option considering its straightforward construction and the therapeutic advantages of dual-drug synergy.

Wound pH-Modulating Strategies for Diabetic Wound Healing

Significance: Chronic diabetic wounds on the lower extremities (diabetic foot ulcers, DFU) are one of the most prevalent and life-threatening complications of diabetes, responsible for significant loss of quality of life and cost to the health care system. Available pharmacologic treatments fail to achieve complete healing in many patients. Recent studies and investigational treatments have highlighted the potential of modulating wound pH in DFU. Recent Advances: Data from in vitro, preclinical, and clinical studies highlight the role of pH in the pathophysiology of DFU, and topical administration of pH-lowering agents have shown promise as a therapeutic strategy for diabetic wounds. In this critical review, we describe the role of pH in DFU pathophysiology and present selected low-molecular-weight and hydrogel-based pH-modulating systems for wound healing and infection control in diabetic wounds. Critical Issues: The molecular mechanisms leading to pH alterations in diabetic wounds are complex and may differ between in vitro models, animal models of diabetes, and the human pathophysiology. Wound pH-lowering bandages for DFU therapy must be tested in established animal models of diabetic wound healing and patients with diabetes to establish a comprehensive benefit-risk profile. Future Directions: As our understanding of the role of pH in the pathophysiology of diabetic wounds is deepening, new treatments for this therapeutic target are being developed and will be tested in preclinical and clinical studies. These therapeutic systems will establish a target product profile for pH-lowering treatments such as an optimal pH profile for each wound healing stage. Thus, controlling wound bed pH could become a powerful tool to accelerate chronic diabetic wound healing.

A smart mask for exhaled breath condensate harvesting and analysis

Recent respiratory outbreaks have garnered substantial attention, yet most respiratory monitoring remains confined to physical signals. Exhaled breath condensate (EBC) harbors rich molecular information that could unveil diverse insights into an individual's health. Unfortunately, challenges related to sample collection and the lack of on-site analytical tools impede the widespread adoption of EBC analysis. Here, we introduce EBCare, a mask-based device for real-time in situ monitoring of EBC biomarkers. Using a tandem cooling strategy, automated microfluidics, highly selective electrochemical biosensors, and a wireless reading circuit, EBCare enables continuous multimodal monitoring of EBC analytes across real-life indoor and outdoor activities. We validated EBCare's usability in assessing metabolic conditions and respiratory airway inflammation in healthy participants, patients with chronic obstructive pulmonary disease or asthma, and patients after COVID-19 infection.

Bioelectronics for electrical stimulation: materials, devices and biomedical applications

Bioelectronics is a hot research topic, yet an important tool, as it facilitates the creation of advanced medical devices that interact with biological systems to effectively diagnose, monitor and treat a broad spectrum of health conditions. Electrical stimulation (ES) is a pivotal technique in bioelectronics, offering a precise, non-pharmacological means to modulate and control biological processes across molecular, cellular, tissue, and organ levels. This method holds the potential to restore or enhance physiological functions compromised by diseases or injuries by integrating sophisticated electrical signals, device interfaces, and designs tailored to specific biological mechanisms. This review explains the mechanisms by which ES influences cellular behaviors, introduces the essential stimulation principles, discusses the performance requirements for optimal ES systems, and highlights the representative applications. From this review, we can realize the potential of ES based bioelectronics in therapy, regenerative medicine and rehabilitation engineering technologies, ranging from tissue engineering to neurological technologies, and the modulation of cardiovascular and cognitive functions. This review underscores the versatility of ES in various biomedical contexts and emphasizes the need to adapt to complex biological and clinical landscapes it addresses.