Hot on the Trail of Nanoscale Heat Conduction

As a Clarivate 2023 Highly Cited Researcher, Dr Zhang Gang is blazing a trail in the field of nanoscale thermal conduction and thermoelectric materials.

Hot on the Trail of Nanoscale Heat Conduction

When Dr Zhang Gang started his study of nanoscale heat conduction 20 years ago, the phenomenon was not well-understood and difficult to investigate.

"At that time, nobody knew how to study thermal conductivity of nano materials. There was no theoretical tool, no references, and no experiments. Computers were slow, so for each simulation we had to wait for a month to get the results. It was very challenging."

Dr Zhang went on to develop a new theoretical methodology and published his findings in 2005. He postulated that heat conduction does not follow Fourier’s law in nano materials and that the thermal properties of nanostructures differ significantly from their bulkier counterparts. Three years later, a UC Berkeley experimental group proved his theoretical prediction, and his work has since become the foundation for nanoscale thermal transport.

Like many scientists before him, Dr Zhang’s interest in science was sown early by an inspirational teacher in school. "When I was attending high school in China, I had a really good Physics teacher who was able to connect what we learnt in class with real life phenomena. I was captivated and I thought then that I would make it my career."

As he progressed in his academic journey, Dr Zhang was fortunate enough to meet mentors who were pivotal in guiding his research directions. His PhD supervisors in Tsinghua University, Professors Bing-Lin Gu and Wenhui Duan, are leaders in computational material science who worked on carbon nanotubes. He later studied under Professor Li Baowen at the National University of Singapore (NUS), who guided him to work on nanoscale thermal transport.

"That cross disciplinary interaction eventually led to my interest in thermal transport in carbon nanotubes."

Dr Zhang, a Senior Principal Scientist at A*STAR's Institute of High Performance Computing (IHPC), is currently working on the thermal conductivity of different 2D materials and exploring using different coatings to increase interfacial thermal conduction.

Hot on the Trail of Nanoscale Heat Conduction

Despite his decades of work in this area, he regards the technology as nascent. "I think we are still at the starting point. But with the theoretical and fundamental research done so far, I hope to see more milestone work and application of knowledge in the industry over the next few years."

Dr Zhang’s first love however remains in fundamental research. In his view, there are still many unexplored areas and questions that remained to be answered in thermal systems.

The father of two teenagers, who have inherited his love for science, hopes to nurture more aspiring scientists in his field. While he highlights the importance of keeping up with technological advances in AI or machine learning, he stresses, "We still need people who understand the fundamentals of physics or chemistry. The platforms and ways of learning may have evolved, but basic science knowledge remains the same."

For young researchers who are passionate about science, he urges them to stay curious and "find an open question where there's no answer and work on that" – just as he did many years ago.