In article number 2302256, John A. Rogers, Ralph G. Nuzzo, Yonggang Huang, and co-workers report a miniaturized, wireless mechanoacoustic sensor, encapsulated with a self-healing, dynamic covalent elastomer, embedded with chemistries that provide colorimetric responses, strain-adaptive stiffening, and thermal insulation properties relevant to the safety of wireless, skin-interfaced bioelectronic device use and operation. These multifunctional materials design strategies can immediately apply to wide ranging classes of devices, and also inspire the development of additional, complementary materials strategies for safe operation of bioelectronic systems.