It has far-reaching applications, particularly in transforming computer chip thermal management through atomic-level design and molecular engineering.
A team of researchers from the University of California, Los Angeles (UCLA), has unveiled a solid-state thermal transistor that leverages an electric field to control the movement of heat within a semiconductor device precisely. This achievement holds promise for many applications, particularly in revolutionising the thermal management of computer chips with its atomic-level design and molecular engineering. This innovation could enhance our understanding of heat regulation within the human body.
The researchers mention that the precision control of how heat flows through materials has been a long-held but elusive dream for physicists and engineers. This new design principle takes a giant 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. Electric transistors have long served as the foundational components of modern information technology, dating back to their development by Bell Labs in the 1940s. These semiconductor devices, with their three terminals (gate, source, and sink), regulate the flow of electrons through a chip when an electric field is applied through the gate. As transistors have continued to shrink over the years, the resulting increase in transistors on a single chip has led to more significant heat generation due to electron movement, which can adversely impact chip performance. While conventional heat sinks passively dissipate heat from hotspots, actively regulating heat has remained challenging.
Prior efforts to tune thermal conductivity have been hampered by reliance on moving parts, ionic motions, or liquid solution components, resulting in slow switching speeds for heat movement. The team’s thermal transistor, which incorporates a field effect and a fully solid-state design, overcomes these limitations, offering high performance and compatibility with semiconductor manufacturing processes. This design exploits the field effect to modulate the thermal conductivity of a material at the atomic level, enabling high-performance heat flux switching with minimal power consumption.
The team achieved record-breaking performance with their electrically gated thermal transistors, boasting switching speeds exceeding 1 megahertz and a 1,300% tunability in thermal conductance, all while maintaining reliable performance for over 1 million switching cycles. They can improve both the speed and size of the thermal switching effect by orders of magnitude over what was previously possible. In their proof-of-concept design, a self-assembled molecular interface acts as a conduit for heat transfer. By toggling an electrical field on and off through a third-terminal gate, the thermal resistance across atomic interfaces is controlled, enabling precise heat movement within the material. The researchers validated the transistor’s performance through spectroscopy experiments and first-principles theory computations accounting for field effects on atomic and molecular characteristics.
This presents scalable technology innovation with the potential to revolutionise sustainable energy in chip manufacturing and performance. It offers an approach to comprehending heat management at the molecular level within living cells, hinting at its broader implications in biology.