Context-aware electromagnetic design for continuously wearable biosymbiotic devices

Wearable continuous diffusion-based skin gas analysis

Biophysical signals such as motion and optically acquired hemodynamics represent foundational sensing modalities for wearables. Expansion of this toolset is vital for the progression of digital medicine. Current efforts utilize biofluids such as sweat and interstitial fluid with primarily adhesively mounted sensors that are fundamentally limited by epidermal turnover. A class of potential biomarkers that is largely unexplored are gaseous emissions from the body. In this work, we introduce an approach to capture emission of gas from the skin with a leaky cavity designed to allow for diffusion-based ambient gas exchange with the environment. This approach, coupled with differential measurement of ambient and in-cavity gas concentrations, allows for the real-time analysis of sweat rate, VOCs, and CO2 while performing everyday tasks. The resulting biosignals are recorded with temporal resolutions that exceed current methodology, providing unparalleled insight into physiological processes without requiring sensor replacement over weeks at a time.

Continuous operation of battery-free implants enables advanced fracture recovery monitoring

Substantial hurdles in achieving a digitally connected body with seamless, chronic, high-fidelity organ interfaces include challenges of sourcing energy and ensuring reliable connectivity. Operation is currently limited by batteries that occupy large volumes. Wireless, battery-free operation is therefore paramount, requiring a system-level solution that enables seamless connection of wearable and implantable devices. Here, we present a technological framework that enables wireless, battery-free implant operation in freely moving subjects, with streaming of high-fidelity information from low-displacement, battery-free implants with little user interaction. This is accomplished using at-distance wirelessly recharged, wearable biosymbiotic devices for powering and communication with fully implantable NFC-enabled implants. We demonstrate this capability with osseosurface electronics that stream bone health insight. Eleven-month-long large animal studies highlight the ability of implants to relay information on bone health without negative impact on the subjects. Clinical translatability is shown through fracture healing studies that demonstrate biomarkers of bone union.

Biosymbiotic haptic feedback - Sustained long term human machine interfaces

Haptic technology permeates diverse fields and is receiving renewed attention for VR and AR applications. Advances in flexible electronics, facilitate the integration of haptic technologies into soft wearable systems, however, because of small footprint requirements face challenges of operational time requiring either large batteries, wired connections or frequent recharge, restricting the utility of haptic devices to short-duration tasks or low duty cycles, prohibiting continuously assisting applications. Currently many chronic applications are not investigated because of this technological gap. Here, we address wireless power and operation challenges with a biosymbiotic approach enabling continuous operation without user intervention, facilitated by wireless power transfer, eliminating the need for large batteries, and offering long-term haptic feedback without adhesive attachment to the body. These capabilities enable haptic feedback for robotic surgery training and posture correction over weeks of use with neural net computation. The demonstrations showcase that this device class expands use beyond conventional brick and strap or epidermally attached devices enabling new fields of use for imperceptible therapeutic and assistive haptic technologies supporting care and disease management.

UV-modification of Ag nanoparticles on α-MoCx for interface polarization engineering in electromagnetic wave absorption

The design of electromagnetic wave absorbing materials (EWAMs) has aroused great attention with the express development of electromagnetic devices, which pose a severe EM pollution risk to human health. Herein, an Ag-doped MoCx composite was designed and constructed through a UV-light-induced self-reduction process. The UV-reduction time was controlled on the α-MoC polymer for 0.5-2 hours for modifying different amounts of Ag. As a result, α-MoC@Ag-1.5 exhibited the strongest RLmin of -56.51 dB at 8.8 GHz under a thickness of 3.0 mm and the widest EAB of 4.96 GHz (12.16-17.12 GHz) covering a substantial portion of the Ku-band at a thickness of 2.0 mm due to the synergy of the conductivity loss and abundant interfacial polarization sites. Additionally, a new strategy for computer simulation technology was proposed to simulate substantial radar cross-sectional reduction values with real far-field conditions, whereby absorbing coatings with α-MoC@Ag-1.5 were proved to contribute to a remarkable radar cross-sectional reduction of 37.4 dB m2.

Biosymbiotic platform for chronic long-range monitoring of biosignals in limited resource settings

Remote patient monitoring is a critical component of digital medicine, and the COVID-19 pandemic has further highlighted its importance. Wearable sensors aimed at noninvasive extraction and transmission of high-fidelity physiological data provide an avenue toward at-home diagnostics and therapeutics; however, the infrastructure requirements for such devices limit their use to areas with well-established connectivity. This accentuates the socioeconomic and geopolitical gap in digital health technology and points toward a need to provide access in areas that have limited resources. Low-power wide area network (LPWAN) protocols, such as LoRa, may provide an avenue toward connectivity in these settings; however, there has been limited work on realizing wearable devices with this functionality because of power and electromagnetic constraints. In this work, we introduce wearables with electromagnetic, electronic, and mechanical features provided by a biosymbiotic platform to realize high-fidelity biosignals transmission of 15 miles without the need for satellite infrastructure. The platform implements wireless power transfer for interaction-free recharging, enabling long-term and uninterrupted use over weeks without the need for the user to interact with the devices. This work presents demonstration of a continuously wearable device with this long-range capability that has the potential to serve resource-constrained and remote areas, providing equitable access to digital health.