Wearable multi-sensing double-chain thermoelectric generator

Abstract

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.

Screen-Printed Flexible Thermoelectric Device Based on Hybrid Silver Selenide/PVP Composite Films

“…Many thermoelectric materials are being explored for power generation applications, such as GeTe [ 22 ], PbTe [ 23 ], half-Heusler [ 24 ], and skutterudites [ 25 ]. The well-studied n-type material of Bi 2 Te 3 is brittle, and the element Te is rare and toxic, which is not favorable for practical applications in wearable devices [ 17 , 26 , 27 , 28 ]. As an “electron crystal, phonon liquid” n-type material, silver selenide (Ag 2 Se) is environmentally friendly and abundant, with high electrical conductivity and low thermal conductivity at room temperature.…”

The Interface between Nanoenergy and Self-Powered Electronics

“…For indirect utilization, nanoenergy can power electronics and control machines with several intermediate steps such as power management modules and signal regulating process. Reproduced with permission from John Springer Nature [ 82 ], Elsevier [ 31 , 48 , 60 , 78 , 83 ], and American Chemical Society [ 47 , 68 , 84 ].…”

Textile-Based Triboelectric Nanogenerators for Wearable Self-Powered Microsystems

“…Energy harvesting from the environment and the human body is a current research hotspot. The existing solar cells [ 6 , 7 ], thermoelectric generators [ 8 , 9 ], and biofuel cells [ 10 , 11 ] are the main methods to harvest energy from the environment and human body, but they require external conditions such as sunlight, temperature, and auxiliary catalysts to work continuously and steadily.…”