I've got a feeling: Sensory (or afferent) nerves bring sensations of touch, pain, or temperature variation to the central nervous system and brain. Using the tools and materials of organic electronics, Kim et al. combined a pressure sensor, a ring oscillator, and an ion gel–gated transistor to form an artificial mechanoreceptor (see the Perspective by Bartolozzi). The combination allows for the sensing of multiple pressure inputs, which can be converted into a sensor signal and used to drive the motion of a cockroach leg in an oscillatory pattern. Science , this issue p. 998 ; see also p. 966

We developed a stretchable organic optoelectronic sensorimotor synapse to mimic a biological optical sensory nervous system.

Skin-like sensory devices should be stretchable and self-healable to meet the demands for future electronic skin applications. Despite recent notable advances in skin-inspired electronic materials, it remains challenging to confer these desired functionalities to an active semiconductor. Here, we report a strain-sensitive, stretchable, and autonomously self-healable semiconducting film achieved through blending of a polymer semiconductor and a self-healable elastomer, both of which are dynamically cross-linked by metal coordination. We observed that by controlling the percolation threshold of the polymer semiconductor, the blend film became strain sensitive, with a gauge factor of 5.75 × 10⁵ at 100% strain in a stretchable transistor. The blend film is also highly stretchable (fracture strain, >1300%) and autonomously self-healable at room temperature. We proceed to demonstrate a fully integrated 5 × 5 stretchable active-matrix transistor sensor array capable of detecting strain distribution through surface deformation.

Electronic second skin is touted as the next interface to expand applications of electronics for natural and seamless interactions with humans to enable smart health care, the Internet of Things, and even to amplify human sensory abilities. Thus, electronic materials are now being actively investigated to construct “second skin.” Accordingly, electronic devices are desirable to have skin‐like properties such as stretchability, self‐healing ability, biocompatibility, and biodegradability. This work reviews recent major progress in the development of both electronic materials and devices toward the second skin. It is concluded with comments on future research directions of the field.