Biomass-Derived, Highly Conductive Aqueous Inks for Superior Electromagnetic Interference Shielding, Joule Heating, and Strain Sensing

Emerging trends and innovations in polysaccharide-derived EMI shielding materials: A comprehensive review of bibliometric and performance analysis

The increasing reliance on electronic devices has created a pressing demand for high-performance and sustainable electromagnetic interference shielding materials. While conventional materials, such as metals and carbon-based composites, offer excellent shielding capabilities, they are hindered by high costs, environmental concerns, and limitations in scalability. Polysaccharide-based materials, including cellulose, chitosan, and alginate, represent a promising alternative due to their biodegradability, renewability, and versatility. These materials, when combined with advanced fillers such as MXene, graphene, silver nanowires (AgNW), carbon nanotubes (CNTs), and magnetic nanoparticles like Fe3O4, exhibit exceptional shielding performance, often exceeding 100 dB, alongside lightweight and flexible characteristics. A detailed bibliometric analysis reveals a rapid growth in global research, with China leading in publication output and international collaborations. Advances in composite design, such as multilayered, gradient, and hybrid architectures, have significantly enhanced the functional capabilities of these materials, including improved absorption-reflection mechanisms, thermal management, and mechanical robustness. Despite these achievements, key challenges persist in optimizing filler dispersion, balancing electrical and mechanical properties, and developing scalable production methods. This review offers critical insights into the untapped potential of underexplored polysaccharides, such as starch and gums, and highlights their suitability for next-generation EMI shielding applications. By exploring the synergy between various fillers and polysaccharide matrices, the article outlines transformative pathways for creating high-performance, sustainable materials. Readers are equipped with actionable perspectives on innovative composite designs, material optimization strategies, and scalable fabrication techniques to address the evolving demands of advanced electronics and environmental sustainability.

Multi-Scale MXene/Silver Nanowire Composite Foams with Double Conductive Networks for Multifunctional Integration

With the onset of the 5G era, wearable flexible electronic devices have developed rapidly and gradually entered the daily life of people. However, the vast majority of research focuses on the integration of functions and performance improvement, while ignoring electromagnetic hazards caused by devices. Herein, the 3D double conductive networks are constructed through a repetitive vacuum-assisted dip-coating technique to decorate the 2D MXene and 1D silver nanowires on the melamine foam. Benefiting from the unique porous structure and multi-scale interconnected frame, the resultant composite foam exhibited high electrical conductivity, low density, superb electromagnetic interference shielding (48.32 dB), and Joule heating performance (up to 90.8 °C under 0.8 V). Furthermore, a single-electrode triboelectric nanogenerator (TENG) with powerful energy harvesting capability is assembled by combining the composite foam with an ultra-thin Ecoflex film and a polyvinylidene fluoride film. Simultaneously, the foam-based TENG can also be considered a reliable wearable sensor for monitoring activity patterns in different parts of the human body. The versatility and scalable manufacturing of high-performance composite foams will provide new design ideas for the development of next-generation flexible wearable devices.

Carbon Nanofibrous Aerogels Derived from Electrospun Polyimide for Multifunctional Piezoresistive Sensors

The fabrication of carbon aerogels with ultralow density, high electrical conductivity, and ultraelasticity still remains substantial challenges. This study utilizes electrospun polyimide aerogel as the source to fabricate flexible carbon nanofibrous aerogel (PI-CNA) capable of multifunctional applications. The lightweight PI-CNA based piezoresistive sensor shows a wide linear range (0-217 kPa), rapid response/recovery time, and fatigue resistance (12,000 cycles). More importantly, the superior pressure sensing enables the PI-CNA for all-range healthcare sensing, including pulse monitoring, physiological activity detection, speech recognition, and gait recognition. Moreover, the EMI SE and the A coefficient of the PI-CNA reach 45 dB and 0.62, respectively, indicating the outstanding absorption dominated EMI shielding effects due to the multiple reflections and absorption. Furthermore, PI-CNA exhibits satisfying Joule heating performance up to 120 °C with rapid response time (10-30 s) under low supply voltages (1.5-5 V) and possesses sufficient heating reliability and repeatability in long-term repeated heating/cooling cycles. The fabricated PI-CNA shows significant potential applications in wearable technologies, energy conversion, electronic skin, and artificial intelligence.

An Electroactive and Self-Assembling Bio-Ink, based on Protein-Stabilized Nanoclusters and Graphene, for the Manufacture of Fully Inkjet-Printed Paper-Based Analytical Devices

Hundreds of new electrochemical sensors are reported in literature every year. However, only a few of them makes it to the market. Manufacturability, or rather the lack of it, is the parameter that dictates if new sensing technologies will remain forever in the laboratory in which they are conceived. Inkjet printing is a low-cost and versatile technique that can facilitate the transfer of nanomaterial-based sensors to the market. Herein, an electroactive and self-assembling inkjet-printable ink based on protein-nanomaterial composites and exfoliated graphene is reported. The consensus tetratricopeptide proteins (CTPRs), used to formulate this ink, are engineered to template and coordinate electroactive metallic nanoclusters (NCs), and to self-assemble upon drying, forming stable films. The authors demonstrate that, by incorporating graphene in the ink formulation, it is possible to dramatically improve the electrocatalytic properties of the ink, obtaining an efficient hybrid material for hydrogen peroxide (H2 O2 ) detection. Using this bio-ink, the authors manufactured disposable and environmentally sustainable electrochemical paper-based analytical devices (ePADs) to detect H2 O2 , outperforming commercial screen-printed platforms. Furthermore, it is demonstrated that oxidoreductase enzymes can be included in the formulation, to fully inkjet-print enzymatic amperometric biosensors ready to use.