Sign‐Switchable Poisson's Ratio Design for Bimodal Strain‐to‐Electrical Signal Transducing Device

Abstract

Stretchable electronic devices that conduct strain‐related electronic performances have drawn extensive attention, functioning as mechanical sensors, actuators, and stretchable conductors. Although strain‐insensitive or strain‐responsive nature is well‐achieved separately, it remains challenging to combine these two characteristics in one single device, which will offer versatile adaptability in various working situations. Herein, a hybrid material with sign‐switchable Poisson's ratio (SSPR) is developed by combining a phase‐change gel based reentrantreentrant honeycomb pattern and a polydimethylsiloxane film. The phase‐change gel featuring thermally‐regulated Young's modulus enables the hybrid material to switch between negative and positive Poisson's ratios. After integrating with a pre‐stretched silver nanowires film, the obtained stretchable device performs bimodal strain‐to‐electrical signal transducing (Bi‐SET) functions, in which the SSPR‐dominated strain‐resistance response switches between strain‐dependent and strain‐insensitive behaviors. As a proof of concept, a mode‐switchable grasping system is constructed using a Bi‐SET device‐based controller, enabling the adaptation of grasping behaviors to various target objects.