Maximized power output of PCB-based vertical micro thermoelectric generators

Abstract Thermoelectric Generators (TEGs) are a promising solution for sustainable energy harvesting in Internet of Things (IoT) devices, offering compactness, reliability, and maintenance-free operation. This paper presents the design, optimization, fabrication, and experimental evaluation of double-sided vertical micro thermoelectric generators (µTEGs) based on printed circuit board (PCB) technology. Building on prior work with single-sided µTEGs, the double-sided design leverages both sides of the PCB substrate to enhance thermal gradient utilization, an enhancement in thermolegs density, maximize power density and power conversion efficiency. Dimensional optimization of thermoleg geometries, including diameter and length, was performed through simulations, considering the specific thermoelectric properties of the materials used, to maximize power output. The optimized design was fabricated using a cost-effective CNC milling process, eliminating cleanroom requirements and reducing production time. Experimental results showed that the double-sided µTEG achieved a maximum power output of 1.78 µW at ΔT = 10 °C, representing a 25.4 % improvement over the baseline design and a 54 % enhancement in power-per-area-of-TC and a 380% improvement in thermolegs density compared to previous single-sided µTEGs. The findings demonstrate the potential of double-sided PCB-based µTEGs as efficient, scalable, and cost-effective solutions for energy harvesting in IoT and similar applications.