Microtrench‐Patterned Elastomeric Substrate for Stretchable Electronics with Minimal Interference by Bodily Motion

Abstract Challenges associated with local stress concentration on layers in stretchable devices under mechanical deformation by bodily motions, which causes strain‐induced signal interference and generates cracks, constitute one of the remaining issues for realization of skin‐attachable stretchable electronics. Herein, a new structural engineering approach is introduced for an elastomeric substrate, a microtrench‐patterned stretchable substrate, in which microtrenches are formed on the substrate backside, effectively mitigating local stress on the surface layers under stretching. Combining the microtrench pattern on the backside and 3D stress‐absorbing microstructured surface on the frontside of the elastomeric substrate for stress engineering results in effective suppression of stress concentration on the crack‐prone carbon paste electrode and piezoresistive pressure sensing layer on the frontside surface due to stress‐concentration on microtrench pattern and, in turn, minimal change in their resistance with deformation. This approach using a simple and facile method to minimize stress in device layers under motion‐induced deformation has great potential for applications of diverse materials for body‐attachable stretchable electronics with minimal strain‐responsiveness.