Flexible and compressible thermoelectric foam for temperature–pressure dual sensor

Thermoelectric materials are traditionally employed in power generation and solid-state refrigeration. However, progress in thermoelectric generators and coolers has slowed in recent years due to high material costs and limited efficiency, prompting exploration into new application area. In this study, we fabricate a composite thermoelectric foam (CTF) by integrating Ag 2 Se nanowires, single-walled carbon nanotubes (SWCNTs), and polystyrene- block -poly(ethylene- ran -butylene)- block -polystyrene (SEBS). The resulting porous structure, combined with the elasticity of SEBS, endows the CTF with ultralight weight (0.33 g cm −3 ), low thermal conductivity (0.38 W m −1 K −1 ), and excellent mechanical resilience, enabling it to withstand 20% tensile strain and fully recover from 60% compressive deformation. Incorporating conductive SWCNTs yields a 6.4-fold increase in thermoelectric figure-of-merit compared to pristine Ag 2 Se foam. Due to the unique structure and improved thermoelectric performance, the Ag 2 Se/SWCNT/SEBS CTF can function effectively as a temperature–pressure dual sensor, with experimentally verified sensitivity to both ambient temperature change and mechanical strain. Our work provides a facile and scalable approach to producing CTFs with controllable thermoelectric and mechanical properties, offering strong potential for sensing applications. A composite thermoelectric foam (CTF) integrating Ag 2 Se nanowires, single-walled carbon nanotubes, and SEBS exhibits ultralight weight, low thermal conductivity, and remarkable elasticity. Conductive SWCNTs enhance the figure-of-merit 6.4-fold, enabling the CTF to serve as a dual temperature–pressure sensor. This scalable design offers tunable thermoelectric and mechanical properties for advanced sensing applications. • Ultralight, elastic Ag 2 Se/SWCNT/SEBS thermoelectric foam with low thermal conductivity. • SWCNT-enabled charge transport yields a 6.4× enhancement in thermoelectric performance. • Room-temperature, solution-based processing enables scalable and low-energy fabrication. • Advanced synchrotron micro-computed tomography (MCT) reveals 3D constituent distribution and structure–property relationships. • Demonstration of a temperature–pressure dual sensor for multifunctional sensing.