Multifunctional durable solid-state thermoelectric sensor enabled by interstitial Co doping in Mg3(Sb, Bi)2

Abstract

<h2>Summary</h2> Mg₃(Sb, Bi)₂-based thermoelectric (TE) reports have focused on increasing conversion efficiency for practical power generation or solid-state cooling, with little investigation into the Seebeck effect in other pioneering fields. This work presents an interstitial cobalt-doping strategy in Mg₃(Sb, Bi)₂-based TEs, achieving a TE power factor of ∼27.3 μW cm⁻¹ K⁻² by improved electrical conductivity, with a compressive strength of ∼400 MPa. More importantly, inspired by optimal carrier mobility and the Seebeck coefficient, a TE sensing prototype device was developed based on Mg_3.19Co_0.01Sb_0.5Bi_1.49Te_0.01 and demonstrated multifunctional sensing capabilities in respiration monitoring, tactile feedback, remote detection, and liquid recognition, broadening the potential applications of conventional solid-state TEs.