Self-Powered Temperature Electronic Skin Based on Island-Bridge Structure and Bi-Te Micro-Thermoelectric Generator for Distributed Mini-Region Sensing

Adv Mater. 2023 Dec;35(52):e2309629. doi: 10.1002/adma.202309629. Epub 2023 Nov 27.

Abstract

Thermoelectric (TE) effect based temperature sensor can accurately convert temperature signal into voltage without external power supply, which have great application prospects in self-powered temperature electronic skin (STES). But the fabrication of stretchable and distributed STES still remains a challenge. Here, a novel STES design strategy is proposed by combining flexible island-bridge structure with BiTe-based micro-thermoelectric generator (µ-TEG). Furthermore, a 4 × 4 vertical temperature sensor array with good stretchability and distributed sensing property has been fabricated for the first time. The interfacial chemical bonds located between the rigid islands (µ-TEG) and the flexible substrate (polydimethylsiloxane, PDMS) endow the STES with excellent stretchability, and its sensing performance remains unchanged under 30% strain (the maximum strain of human skin). Moreover, the STES sensing unit possesses high sensitivity (729 µV K-1 ), rapid response time (0.157 s), and high spatial resolution (2.75 × 2.75 mm2 ). As a proof of concept, this work demonstrates the application of the STES in the detection of mini-region heat sources in various scenarios including noncontact spatial temperature responsing, intelligent robotic thermosensing, and wearable temperature sensing. Such an inspiring design strategy is expected to provide guidance for the design and fabrication of wearable self-powered temperature sensors.

Keywords: Bi-Te micro-thermoelectric generator; island-bridge structure; temperature sensing electronic skin; thermoelectric effect.