UCLA Researchers Show Off a "Transistor for Heat" Capable of Switching a Million Times Per Second
Like traditional electronic transistors, the "thermal transistor" can be switched on and off — but to control the flow of heat.
Researchers from the University of California, Los Angeles (ULCA) have demonstrated a device they describe as "a transistor for heat" — a solid-state component which can switch between insulating heat and letting it through, and which could be key to making future electronics as efficient as possible.
"The precision control of how heat flows through materials has been a long-held but elusive dream for physicists and engineers," claims co-author Yongjie Hu, professor of mechanical and aerospace engineering at the UCLA Samueli School of Engineering, of the team's work. "This new design principle takes a big leap toward that, as it manages the heat movement with the on-off switching of an electric field, just like how it has been done with electrical transistors for decades."
The "thermal transistor" developed by the team is fully solid-state with no moving parts, using a field effect to modulate its conductivity when electricity is applied. In testing, prototypes were able to switch at a rate of 1MHz — one million times a second — with a 1,300 percent tunability in their ability to conduct heat.
"This work is the result of a terrific collaboration in which we are able to leverage our detailed understanding of molecules and interfaces to make a major step forward in the control of important materials properties with the potential for real-world impact," claims co-author Paul Weiss, professor of chemistry and biochemistry. "We have been able to improve both the speed and size of the thermal switching effect by orders of magnitude over what was previously possible."
In terms of practical applications, the thermal transistor could be used to handle the heat created by ever-more-powerful yet increasingly-small electrical transistors in computing chips — potentially boosting both performance and efficiency. Hu also suggests it could "provide insights for the molecular-level mechanisms for living cells," helping to uncover how heat is managed at a fundamental level within the human body.
The team's work has been published in the journal Science under closed-access terms.
Main article image courtesy of H-Lab/UCLA.
