Lee Byeongmoon, Cho Hyeon, Park Kyung Tae, Kim Jin-Sang, Park Min, Kim Heesuk, Hong Yongtaek, Chung Seungjun
Department of Electrical and Computer Engineering, Inter-University Semiconductor Research Center (ISRC), Seoul National University, Seoul, 08826, Korea.
Soft Hybrid Materials Research Center, Korea Institute of Science and Technology, Seoul, 02792, Korea.
Nat Commun. 2020 Nov 23;11(1):5948. doi: 10.1038/s41467-020-19756-z.
Softening of thermoelectric generators facilitates conformal contact with arbitrary-shaped heat sources, which offers an opportunity to realize self-powered wearable applications. However, existing wearable thermoelectric devices inevitably exhibit reduced thermoelectric conversion efficiency due to the parasitic heat loss in high-thermal-impedance polymer substrates and poor thermal contact arising from rigid interconnects. Here, we propose compliant thermoelectric generators with intrinsically stretchable interconnects and soft heat conductors that achieve high thermoelectric performance and unprecedented conformability simultaneously. The silver-nanowire-based soft electrodes interconnect bismuth-telluride-based thermoelectric legs, effectively absorbing strain energy, which allows our thermoelectric generators to conform perfectly to curved surfaces. Metal particles magnetically self-assembled in elastomeric substrates form soft heat conductors that significantly enhance the heat transfer to the thermoelectric legs, thereby maximizing energy conversion efficiency on three-dimensional heat sources. Moreover, automated additive manufacturing paves the way for realizing self-powered wearable applications comprising hundreds of thermoelectric legs with high customizability under ambient conditions.
热电发电机的柔性化有助于与任意形状的热源实现共形接触，这为实现自供电可穿戴应用提供了契机。然而，由于高热阻聚合物基板中的寄生热损失以及刚性互连导致的热接触不良，现有的可穿戴热电装置不可避免地表现出热电转换效率降低的问题。在此，我们提出了具有固有可拉伸互连和软热导体的柔性热电发电机，可同时实现高热电性能和前所未有的顺应性。基于银纳米线的软电极连接碲化铋基热电腿，有效吸收应变能，使我们的热电发电机能够完美贴合曲面。在弹性体基板中通过磁自组装形成的金属颗粒构成软热导体，显著增强了向热电腿的热传递，从而在三维热源上最大化能量转换效率。此外，自动化增材制造为在环境条件下实现包含数百个具有高定制性的热电腿的自供电可穿戴应用铺平了道路。
