High-performance integrated chip-level thermoelectric device for power generation and microflow detection

Miniaturized thermoelectric devices (TED) possess great benefits in energy converting and sensing. By employing improved microfabrication technology, we succeed made an ultra-highly integrated TED with enhanced interfacial and structural qualities at a high filling factor of 61 %. Our micro-TED (2 cm × 2 cm×6 µm, 10,082 TE pairs) achieved an open-circuit voltage up to 2.6 V, an output power of 1.2 mW (temperature difference of 62.8 K). The micro-TED delivered a large temperature gradient up to ∼600 K/mm with input current, achieving a net cooling temperature of 3.6 K with a 3 µm thick thermoelectric layer. As a novel microflow sensor, micro-TED can distinguish ultra-slow cold/hot airflows down to 4 mm/s. The ultra-thin integrated micro-TED can find multi-featured applications in ultra-low-grade thermal energy harvesting, localized chip-to-chip cooling, and hypersensitive sensing. [Display omitted] •Reliable micro-TED with ultra-high integration is fabricated.•Micro-TED shows high open-circuit voltage and output power density.•Micro-TED delivers temperature gradient up to ∼600 K/mm with input current.•Micro-TED recognizes cold/hot airflow down to 4 mm/s.