Professor Wang Zuankai, from the Department of Mechanical Engineering, is leading a team of scientists from different disciplines in a project titled “Bio-inspired surface engineering for phase change heat transfer: From fundamental understanding to practical applications”, which was awarded about HK$5.5 million.

The study is in response to the pressing need for techniques to enhance heat transfer in various high heat flux devices in industries such as microelectronics, nuclear power plants, water desalination and aerospace.  

The project team will focus on developing a general bio-inspired approach to fundamentally change and optimise the phase transitions between solid, liquid and vapour for enhanced heat transfer by controlling surface morphology and chemistry.   

Professor Wang said their project was inspired by the water harvest phenomenon in cactus and the trapping of the liquid layer on the pitcher plant surface. The team will develop a novel condensation surface for harnessing latent heat, and will also explore how to suppress the formation of ice without sacrificing condensation heat transfer to reduce energy consumption.   

“Bio-inspired interfacial surfaces have received increasing attention. We hope the project will help establish important scientific ground for breakthroughs in interfacial sciences and thermal engineering, and hence assist in the design of robust techniques to address some of the energy challenges facing us today,” Professor Wang said. 

The team has a strong track record in research in bio-inspired surfaces. Over the past four years, research work led by Professor Wang has been published in high-impact journals such as Science, Science Advances, Nature Physics, Nature Communications, Physical Review Letters, ACS Nano, and Advanced Functional Materials. He has also set a Guinness World Record for his research on the development of novel water repellent surfaces, by reducing the contact time between a liquid drop and a solid surface by 80%.

The result of this collaborative research project will have a significant impact on energy saving and security, Professor Wang added. Scientists from The Chinese University of Hong Kong, The Hong Kong University of Science and Technology, and The University of Hong Kong will work with Professor Wang and his team on the three-year project.

 

Professor Lee Chun-sing, Head of the Department of Chemistry and Chair Professor of Materials Chemistry, together with scientists from five other local universities, will use HK$5.7 million of the CRF grant to establish a multi-function surface analysis system with time-resolved two-photon photoemission (TR-2PPE) spectroscopy. This new facility will be used for research on chemical and fast electronic processes of less than one nano second, or one-billionth of a second (<10^-9 s) in the fields of physics, materials science and chemistry. 
 
In additional to conventional light sources, such as x-ray and ultraviolet light, the new facility is equipped with an ultra-fast pump-probe laser and a high speed detector. TR-2PPE measures the electronic structure of materials as a function of the time delay between pump-probe laser pulses; and allows in-depth analysis on ultra-fast electron processes and interactions. TR-2PPE is a versatile and powerful technique for time-resolved studies on charge interactions, chemical reactions and kinetics, as well as dynamic studies. This project will equip Hong Kong’s researchers with a state-of-the-art facility for studying fast electronic processes in advanced materials for energy, optoelectronic and biomedical applications.