Reconfigurable flexible thermoelectric generators based on all-inorganic MXene/Bi2Te3 composite films

Flexible thermoelectric generators (FTEGs) represent an excellent solution for energizing wearable electronics, capitalizing on their ability to transform body heat into electrical energy. Nevertheless, their use in the wearable industry is limited by the insufficient thermoelectric (TE) efficiency of materials and the minimal temperature variation among the devices. In this study, we have developed a Lego-like reconfigurable FTEG by combining flexible TE chips, rheological liquid-metal electrical wiring, and a stretchable substrate in a mechanical plug-in configuration. The flexible TE chips are constructed from n-type all-inorganic MXene/Bi₂Te₃ composite films, which have their TE properties further enhanced through heat treatment. A demonstration of the FTEG illustrates its capability to convert heat into vertical temperature difference (ΔT), leading to a substantial ΔT at the cold end in contact with the environment, resulting in a power output of 7.1 μW with a ΔT of 45 K from only 5 TE chips. The reconfigurable FTEG presents significant potential for wearable devices to harness low-grade heat.