Computing capabilities that once required gigantic machines can now fit in the palm of your hand. As more processing power is squeezed into increasingly compact devices, managing heat has become a major challenge.
“At very small scales, heat carriers bump into surfaces and boundaries so often that heat gets trapped instead of flowing away,” explained Hong-Son Chu, a Principal Scientist at the A*STAR Institute of High Performance Computing (A*STAR IHPC). “If this heat is not managed properly, devices can overheat, slow down or even fail.”
To address this problem, Chu and Rosmin Elsa Mohan, a Scientist at A*STAR IHPC have been investigating how heat transfer in electronics can be better controlled to enable smaller, faster and cooler devices. Working with Sunmi Shin, Sichao Li and Jingxuan Wang from the Department of Mechanical Engineering, College of Design and Engineering, National University of Singapore, the team developed a specialised thermometry platform to study surface phonon polaritons (SPhPs)—unusual heat carriers that could play a key role in nanoscale thermal transport.
SPhPs arise from strong interactions between infrared light and atomic vibrations in certain materials. One of their most promising features is their ability to travel long distances—up to hundreds of micrometres—allowing heat to flow efficiently along nanostructures, explained Chu. However, because SPhPs are difficult to detect and measure, their practical use in electronic cooling has remained limited.
To better understand and quantify how these carriers transport heat, the researchers developed a thermometry device designed specifically to probe SPhP-mediated heat conduction at the nanoscale. Resembling a microscopic bridge with built-in thermometers, the platform consists of two suspended beams connected by a nanowall channel made of silicon dioxide. When one beam is gently heated, the other detects the amount of heat transferred across the channel.
Crucially, the sensing beam incorporates nanoscale grating patterns designed by the team. “These grooves help ‘catch’ and absorb the SPhPs more effectively, improving our ability to characterise these special carriers,” said Mohan.
Using this setup, the researchers demonstrated the surprisingly high efficiency with which SPhPs can transport heat across nanoscale gaps. They also showed that incorporating grating patterns enhances control over heat flow, prompting ongoing work to refine these surface designs for even better performance. With carefully engineered patterns, future thermometry platforms could focus infrared energy to create favourable conditions for SPhP generation, while enabling more sensitive heat measurements.
Looking ahead, the team plans to combine this experimental approach with artificial intelligence methods to identify new materials and structures that further enhance thermal transport. “The exceptional heat transfer efficiency of SPhPs could revolutionise thermal management in semiconductor chips, photonic devices and sensors,” said Chu. “This could lead to more reliable components in high-performance computing and next-generation electronic-photonic integrated circuits, where heat remains a major bottleneck.”
The A*STAR-affiliated researchers contributing to this research are from the A*STAR Institute of High Performance Computing (A*STAR IHPC).
