Wearable multi-sensing double-chain thermoelectric generator

Wearable electronics play a crucial role in advancing the rapid development of artificial intelligence,and as an attractive future vision,all-in-one wearable microsystems integrating powering,sensing,actuating and other functional components on a single chip have become an appealing tendency.Herein,we propose a wearable thermoelectric generator(ThEG)with a novel double-chain configuration to simultaneously realize sustainable energy harvesting and multi-functional sensing.In contrast to traditional single-chain ThEGs with the sole function of thermal energy harvesting,each individual chain of the developed double-chain thermoelectric generator(DC-ThEG)can be utilized to scavenge heat energy,and moreover,the combination of the two chains can be employed as functional sensing electrodes at the same time.The mature mass-fabrication technology of screen printing was successfully introduced to print n-type and p-type thermoelectric inks atop a polymeric substrate to form thermocouples to construct two independent chains,which makes this DC-ThEG flexible,high-performance and cost-efficient.The emerging material of silk fibroin was employed to cover the gap of the fabricated two chains to serve as a functional layer for sensing the existence of liquid water molecules in the air and the temperature.The powering and sensing functions of the developed DC-ThEG and their interactions were systematically studied via experimental measurements,which proved the DC-ThEG to be a robust multi-functional power source with a 151 mV open-circuit voltage.In addition,it was successfully demonstrated that this DC-ThEG can convert heat energy to achieve a 3.3 V output,matching common power demands of wearable electronics,and harvest biothermal energy to drive commercial electronics(i.e.,a calculator).The integration approach of powering and multi-functional sensing based on this new double-chain configuration might open a new chapter in advanced thermoelectric generators,especially in the applications of all-in-one self-powered microsystems.