UCLA researchers have developed a first-of-its-kind solid-state thermal transistor that could one day be used to better control heat in electronic devices. This technology, combined with other advanced technologies, can help design faster and more powerful processors.

Heat is the number one enemy of electronic devices. As the Institute of Electrical and Electronics Engineering (IEEE) correctly points out, heat sinks have historically been used to passively remove excess heat away from heat sources. Active methods involving moving parts or fluids have also been successful, but they require time to lift effectively to meet load requirements.

In contrast, thermal transistors are designed to control heat flow using electric fields. As IEEE explains, the researchers' thermal transistor utilizes a thin film of molecules that acts as a channel for the transistor. By applying an electric field, the bonds in the film become stronger, increasing its thermal conductivity.

The team's thermal transistor is intriguing in many ways. First, compared to other heat dissipation methods, it requires only a small amount of electrical energy to control heat flow, and the thermal conductivity is 13 times higher than molecular motion solutions. What's more, it can be used in multiples on a single package to improve thermal performance, but also helps target hot spots in new designs such as three-dimensional stacked chips.

Lead author Yongjie Hu noted that scientists and engineers have long had a strong desire to control heat transfer the same way they control electronic devices, but this has been a challenging endeavor.

The best part is, it's not an either/or situation where you have to choose one cooling method over another. There is no reason why thermal transistors cannot be paired with other emerging technologies such as alternative substrates, new designs and existing cooling technologies to achieve optimal results.

The team's related research was recently published in the journal Science:

https://www.science.org/doi/10.1126/science.abo4297

While promising, Hu acknowledged that the technology is still in its early stages of development and future iterations must demonstrate better performance.