Liquid‐State Optoelectronics Using Liquid Metal

Abstract Liquid‐state electronics utilizing functional liquids confined in soft templates as the sensing and actuating component present the ideal platform for enabling conformal coverage of electronic systems on curved and soft surfaces. However, to date, optoelectronic devices based on functional liquid materials as represented by photodetectors and optical memories still have not been proposed; this advancement is crucial to scaling up current liquid‐state devices to a system level. Optoelectronic devices based on liquid metal and photo‐switchable ionic liquid with liquid–liquid heterojunction technology are proposed. The sensing and memory schemes presented are generic for different liquid‐state devices and that enables different functionality to be added to the liquid‐state electronics. As a proof of concept, demonstrations are made of a light sensor composed of the ionic liquid and an optical memory using a composite of the ionic liquid and polypropylene glycol. These devices are important advancements toward the realization of liquid‐state electronic systems.