Redesign high-performance flexible thermoelectrics: From mathematical algorithm to artificial cracks

This work presents a high-performance flexible thermoelectric device (f-TED) by rationally introducing the mathematical algorithm cyclotomic rule into flat-to-flexible inorganic/organic hybrid device design. Artificial cracks and selected substrate-cutting are integrated to realize full flexibility with 0-360° bending angle and low contact resistance. Experimental measurements and numerical simulations as well as contact resistance models indicate and verify the high energy efficiency and power output of the f-TED under various temperature differences and artificial cracks. Noticeably, 19.6 mW/cm power density and ∼3% power conversion efficiency are achieved at near room temperature (53 K temperature difference) for the bismuth telluride f-TED with a 360° bending angle. These results offer feasibility to use the f-TED for energy generation and thermal management of heat source/sink with different surface curvature, especially in self-powered wearable mechatronics and flexible chip cooling in the Internet of Things.