Assemblable thermoelectric Lego blocks for reconfigurable, self-healing, and flexible power generators

Abstract Thermoelectric devices offer a promising route for waste-heat recovery, yet conventional modules—consisting of multiple pairs of inorganic legs soldered to rigid metal electrodes—are intrinsically brittle and nearly impossible to repair or reconfigure once fabricated. Although recent incorporation of flexible or stretchable polymeric components has improved mechanical deformability, these integrated architectures cannot be modified for new functions or restored. In this study, we propose the concept of Lego-like thermoelectric leg blocks that enable on-demand repair and reconfiguration via modular assembly. Each block operates as an independent unit comprising PDMS-based, self-healing Ag-flake-embedded composite electrodes and 3D-printed BiSbTe and BiTeSe thermoelectric legs, yielding flexible, repairable, and modular devices. Assembled devices preserve performance under bending (radius ≈ 3.4 mm), stretching (40%), and even after cutting and reassembly. Moreover, repeated disassembly/reassembly into diverse geometries proceeds without measurable loss in power output. Our Lego-like blocks provide a versatile thermoelectric platform that combines flexibility, reparability, and reconfigurability.