Relative leg-height optimization of micro-thermoelectric coolers for enhanced cooling performance

Micro thermoelectric devices (μTEDs) have emerged as a promising solution for hot-spot cooling and energy-autonomous sensing, while offering fabrication compatibility with on-chip integration 1 . Maximizing performance requires geometric optimization to match the electrical and thermal transport properties of the n-type and p-type materials, typically achieved by adjusting the cross-sectional areas. However, this limits the maximum packing density. Here we present a design strategy for micro thermoelectric coolers (μTECs) that instead optimizes the relative heights of n-type and p-type legs while maintaining a constant cross-sectional area. This approach enables a higher packing density, enhances the cooling power density, and reduces the volume of thermoelectric material, which is often toxic and expensive. The optimized μTEC exhibits a temperature drop of 10.5 K at 293 K and 26.4 K at 373 K. Finite element simulations indicate that cooling power densities of hundreds of watts per square centimeter can be achieved. Our results demonstrate that μTEDs are well suited for hot-spot cooling, while enabling higher circuit integration density, and support compact and energy-autonomous Internet of Things devices.