Nanowerk February 21, 2023
Although several thermal transistors are demonstrated, the use of liquid electrolytes may limit the application from the viewpoint of reliability or liquid leakage. An international team of researchers (Japan, South Korea) constructed and demonstrated a solid-state thermal transistor that can electrochemically control the heat flow with an on-to-off ratio of the thermal conductivity without using any liquid. They constructed thermal transistor on an yttrium oxide-stabilized zirconium oxide base, which also functioned as the switching material, and used strontium cobalt oxide as the active material. Platinum electrodes were used to supply the power required to control the transistor. The thermal conductivity of the active material in the “on” state was comparable to some liquid-state thermal transistors. In general, thermal conductivity of the active material was four times higher in the “on” state compared to the “off” state. Further, the transistor was stable over 10 use cycles, better than some current liquid-state thermal transistors. This behavior was tested across more than 20 separately fabricated thermal transistors, ensuring the results were reproducible. The only drawback was the operating temperature of around 300°C… read more. Open Access TECHNICAL ARTICLE
Design of a solid-state electrochemical thermal transistor… Credit: Advanced Functional Materials, 21 February 2023