Multifunctional Materials Strategies for Enhanced Safety of Wireless, Skin‐Interfaced Bioelectronic Devices

Many recently developed classes of wireless, skin‐interfaced bioelectronic devices rely on conventional thermoset silicone elastomer materials, such as poly(dimethylsiloxane) (PDMS), as soft encapsulating structures around collections of electronic components, radio frequency antennas and, commonly, rechargeable batteries. In optimized layouts and device designs, these materials provide attractive features, most prominently in their gentle, noninvasive interfaces to the skin even at regions of high curvature and large natural deformations. Past studies, however, overlook opportunities for developing variants of these materials for multimodal means to enhance the safety of the devices against failure modes that range from mechanical damage to thermal runaway. This study presents a self‐healing PDMS dynamic covalent matrix embedded with chemistries that provide thermochromism, mechanochromism, strain‐adaptive stiffening, and thermal insulation, as a collection of attributes relevant to safety. Demonstrations of this materials system and associated encapsulation strategy involve a wireless, skin‐interfaced device that captures mechanoacoustic signatures of health status. The concepts introduced here can apply immediately to many other related bioelectronic devices. Safe operation of recently developed classes of wireless, skin‐interfaced biosensors is critically important to the widespread adoption of these technologies in healthcare, particularly for vulnerable patient populations. This study presents a collection of soft materials strategies for the encapsulating structures of these devices that enhance their safety through features in autonomic self‐healing, reversible thermo/mechanochromism, strain‐adaptive stiffening, and thermal insulation properties.