Flexible Thermoelectric Energy Harvester with Stacked Structure of Thermoelectric Composite Films Made of PVDF and Bi₂Te₃-Based Particles

Flexible thermoelectric energy harvesters (f-TEHs) enable wearable sensors or electronic devices to be attached on curved objects with a thermal source. We demonstrated a stacked-structured f-TEH that generates thermal energy without increasing its cross-sectional area. The device consists of thermoelectric composite films fabricated by p- and n-type Bi₂Te₃ and poly(vinylidene fluoride), Al foil and polyethylene terephthalate film. The output performance improved as the number of thermoelectric film layers (L) increased, and the L = 8 f-TEH generated maximum voltage, current, and power. Multiphysics simulations and bending tests were adopted for further investigation. This study demonstrates a distinctive configuration and comprehension of its energy generation mechanism.