Miniaturized Mg₃Bi₂-based thermoelectric cooler for localized electronic thermal management

Miniaturized thermoelectric coolers, known for their high cooling power density and rapid thermal response, hold promise for localized thermal management. While traditional thermoelectric coolers have primarily relied on Bi₂Te₃ alloys, the recent development of n-type Mg₃Bi₂-based materials presents a compelling alternative, offering enhanced cost-effectiveness and environmental sustainability. In this study, we have designed and fabricated a Mg₃Bi₂-based miniscale thermoelectric cooler. At the hot-side temperature of 300 K, the cooler achieves a maximum cooling temperature difference of ~59.0 K, a cooling power density of ~5.7 W cm^-2, and a cooling speed of 65 K s^-1, which surpasses the state-of-the-art Mg₃Bi₂-based devices. In addition, the miniaturized Mg₃Bi₂-based cooler maintains its cooling performance after cyclic electrical current density between 1 A mm^-2 and 3 A mm^-2 for approximately 3,000 cycles. Notably, this miniscale cooler has been applied to provide localized cooling for the central processing unit in a microcontroller. Our findings highlight the potential of Mg₃Bi₂-based miniscale coolers, offering new possibilities for localized thermal management in electronic devices.