Direct Ink 3D Writing of Thermoelectric Materials and Devices

Thermoelectric (TE) power generation can provide a unique solution to convert this dissipated, wasted heat into useful energy, that is, electricity. The performance of thermoelectric modules, typically composed of cuboid-shaped materials, depends on both the materials’ intrinsic properties and the temperature difference created. Despite significant advancements in the development of efficient materials, macroscopic thermal designs capable of accommodating larger temperature differences have been largely underexplored because of the challenges associated with processing bulk thermoelectric materials. At this moment, three-dimensional (3D) printing technology can maximize the flexibility in the design and fabrication of TE modules into more efficient structures. Herein, we present the 3d direct ink writing fabrication of various thermoelectric materials and power generators. The particle-based colloid inks were formulated to exhibit desired rheological properties through the electroviscous effect, tailored by the surface charges. The printed thermoelectric materials exhibit comparable thermoelectric properties to those of materials synthesized by conventional metallurgical methods. Furthermore, combined with the finite element modeling, the macroscopic geometries are designed and realized by the 3D printing processes, leading to significant enhancements in the temperature difference within devices and the resulting output powers. The proposed approach paves the way for designing efficient thermoelectric power generators.