Micro thermoelectric generators (µTEGs) can harvest waste heat to generate electricity, making them a potential solution to the growing problem of powering autonomous electronics, such as sensors for the Internet of Things. Until now, µTEGs have not been able to provide power for these applications. This is because the output power of µTEGs is limited due to insufficient contacts and poor thermal coupling between the device and the heat source. In this work, the contact resistance as well as the thermal coupling between the heat source and the device through process optimization are improved. The former by improved electrochemical deposition (ECD) conditions, the latter by introducing a thin solder adhesion layer, which smooths the uneven surface of µTEG due to its good wetting properties. Using these improvements in combination with optimized packing density, here the fabrication and characterization of a µTEG with 126 leg pairs connected in series are reported that exhibits an open circuit voltage of 339.2 mV at a temperature difference of 20.6 K and a record‐high normalized power density of 25.1 µW cm−2 K−2 for ECD based µTEGs. This µTEG is used to power a temperature sensor, bringing this work one step closer to application.

中文翻译：

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用于为 IoT 供电的高功率密度微型热电发电机


微型热电发电机 （μTEG） 可以收集废热来发电，使其成为解决日益严重的自主电子设备（如物联网传感器）供电问题的潜在解决方案。到目前为止，μTEG 还无法为这些应用供电。这是因为由于触点不足以及器件与热源之间的热耦合不良，μTEG 的输出功率受到限制。在这项工作中，通过工艺优化改善了接触电阻以及热源和器件之间的热耦合。前者通过改进电化学沉积 （ECD） 条件，后者通过引入薄的焊料粘附层，由于其良好的润湿性能，可以平滑 μTEG 的不平整表面。将这些改进与优化的封装密度相结合，本文报道了具有 126 个串联支路对的 μTEG 的制造和表征，该 μTEG 在 20.6 K 的温差下表现出 339.2 mV 的开路电压和创纪录的 25.1 μW cm-2 K-2 标准化功率密度基于基于 ECD 的 μTEG。该 μTEG 用于为温度传感器供电，使这项工作离应用更近了一步。