Micro-heat sink based on silicon nanowires formed by metal-assisted chemical etching for heat dissipation enhancement to improve performance of micro-thermoelectric generator

This work demonstrates the micro-heat sink based on silicon nanowires formed by metal-assisted chemical etching (MACE) for heat dissipation enhancement to improve the performance of the micro-thermoelectric generator (µ-TEG). The heat dissipation through the micro-heat sink is enhanced by increasing the surface-to-volume ratio, which can be achieved by combining deep reactive ion etching (RIE) and MACE. Silicon nanowires with a diameter of 100 nm and a height of 9 µm are successfully formed in both horizontal and vertical surface directions. The micro-heat sink effectiveness is 8.3 times better than that of without employing the micro-heat sink. In addition, the performance of the µ-TEG has been significantly enhanced by utilizing the micro-heat sink. The maximum output power of the µ-TEG with and without the micro-heat sink are 93 µW and 18.5 µW, respectively, under the same evaluation conditions. The findings in this work may be useful not only for the µ-TEG, but also other applications such as micro-supercapacitors, micro-sensors, chemical analysis, and biological processes, which require a large surface-to-volume ratio.