High-performance thermoelectric cooler fabricated vith extrusion-based 3D printing materials

A thermoelectric cooler is a solid-state device that transfers heat from one side to another when an electrical current passes through it. This technology is appealing because it can provide precise and localized cooling and heating without using hazardous liquids or gases commonly found in traditional vapor compression refrigeration. These devices are compact, customizable in size, work in any orientation, operate noiselessly, and require minimal maintenance. Even though thermoelectric coolers could be transformative for many advanced thermal management applications, their widespread adoption is hindered by the low efficiency of the thermoelectric materials and costly manufacturing processes. In this work, we use extrusion-based 3D printing techniques to fabricate high-performance thermoelectric materials using nanomaterial-based ink. The ink formulation is optimized to ensure structural integrity and particle interfacial bonding during annealing, providing p- and n-type materials with record-high zT values of 1.46 and 1.35 at room temperature, respectively. Moreover, we integrate the printed materials into a 32-pair device and achieve a significant cooling temperature gradient of 50 °C and a coefficient of performance of 3.8, comparable to best-performing thermoelectric coolers, avoiding material waste, and the energy-intense and inefficient steps, such as high-temperature synthesis, pressure-assisted sintering, and cutting and dicing ingots, commonly used in conventional manufacturing processes.