Miniaturized Mg₃Bi₂-based thermoelectric cooler for localized electronic thermal management

Area of Science:

• Materials Science
• Thermoelectrics
• Solid State Physics

Background:

• Miniaturized thermoelectric coolers (TECs) are crucial for localized thermal management due to high cooling power density and rapid thermal response.
• Traditional TECs often use Bi2Te3 alloys, but n-type Mg3Bi2-based materials offer a more cost-effective and environmentally sustainable alternative.
• Existing Mg3Bi2-based TECs have shown promise but require further optimization for advanced applications.

Purpose of the Study:

• To design and fabricate a high-performance Mg3Bi2-based miniscale thermoelectric cooler.
• To evaluate the cooling performance, including temperature difference, cooling power density, and cooling speed.
• To assess the device's durability under cyclic electrical loading and demonstrate its application in electronic device cooling.

Main Methods:

• Fabrication of a miniscale thermoelectric cooler utilizing n-type Mg3Bi2-based materials.
• Experimental characterization of the cooler's performance at a hot-side temperature of 300 K.
• Testing the cooler's stability through approximately 3,000 cycles of varying electrical current density (1–3 A mm−2).
• Integration and testing of the cooler for localized cooling of a central processing unit (CPU) in a microcontroller.

Main Results:

• The Mg3Bi2-based miniscale cooler achieved a maximum cooling temperature difference of ~59.0 K.
• It demonstrated a high cooling power density of ~5.7 W cm−2 and a rapid cooling speed of 65 K s−1.
• The device maintained stable cooling performance over 3,000 cycles of electrical current density.
• Successful application in providing localized cooling for a microcontroller's CPU.

Conclusions:

• The developed Mg3Bi2-based miniscale thermoelectric cooler surpasses the performance of state-of-the-art Mg3Bi2 devices.
• The cooler exhibits excellent thermal management capabilities and long-term operational stability.
• Mg3Bi2-based miniscale TECs present a viable and sustainable solution for localized cooling in electronic devices.