Peritectic engineering enhanced thermoelectrics for smart thermal messaging devices

Autonomous, bio-integrated electronic systems, such as smart prosthetics and functional electronic skins, require materials combining energy harvesting with perception. Although Indium Antimonide is well established in high-speed electronics owing to its high electron mobility, yet its large intrinsic thermal conductivity has limited its use in thermoelectric energy harvesting. Here, we introduce a peritectic engineering strategy to reduce the thermal bottleneck. Thermodynamic control of the peritectic reaction generates hierarchical InBi@(Bi, Sb) core-shell nanostructures that reduce the room-temperature lattice thermal conductivity from 13.1 to 6.84 W m⁻¹ K⁻¹. This microstructural manipulation raise the power factor by 98% at 473 K, yielding a marked decoupling of electron and phonon transport. A compact, self-powered InSb-InBi/Cu₃InSnSe₅ module drives commercial electronics under moderate thermal gradients. The module also functions as a zero-power thermo-tactile interface for prosthetic limbs, enabling covert thermal messaging via Morse code decoded by a transfer learning algorithm a transfer learning algorithm. This platform enables the integration of thermoelectric materials into intelligent human-machine interfaces, advancing the development of self-powered sensory systems.