In the past two years HKBU has had a magnificent record of success at the world’s largest invention showcase, the International Exhibition of Inventions of Geneva, winning a total of 15 awards at the 44th and 45th exhibitions. Of the inventions submitted by HKBU, one that was particularly impressive and drew wide media attention was ArmoGlass, an ultra-hard anti-scratch thin film invented by Professor Cheah Kok Wai, Chair Professor of the Department of Physics. This invention, which is perfect for producing ultra-hard anti-scratch covers for touch screen devices, stood out from 1,000 projects entered from 40 countries at the Exhibition in 2016 and attained the Grand Prix Award, the Gold Medal in the Industrial Processes Category and the Special Award For The Invention. As well as being an honour for Professor Cheah and HKBU, the awards reflected well on the academic sector of Hong Kong. In 2016, Professor Cheah was appointed Dr. Elizabeth K.S. Law Endowed Chair of Advanced Materials*.

Everyone from the Department of Physics knows who Professor Cheah is because he is the first scholar at HKBU to have secured a patent. Also, the organic LED (light-emitting diode) that he invented lifted HKBU’s research on advanced materials to the international level. Moreover, Professor Cheah is also widely recognised internationally, in part because he has presented or published more than 290 papers at international conferences and in top-tier journals. The strong impact of his publications is evidenced by his exceptionally high citation count on Google Scholar of over 7,800. He is also a Fellow of the Institute of Physics in the UK. He is warmly appreciated by the media because he is adept at giving clear and understandable explanations of complex physics topics. He has also taken root in the minds of the general public, thanks to his trademark style that includes his signature bow tie and moustache.

Driven by curiosity
According to Professor Cheah, as a child he was full of eager curiosity and was always full of ideas. His constantly inquisitive mindset means that he is never out of touch with the younger generation, and this helps him maintain a close relationship with his students. He likes brainstorming with his team and this definitely helps with their joint research efforts. Take his Sapphire thin film invention as an example of how good teamwork benefits research. Professor Cheah recalled that it did not take long for his team to develop this invention because the sapphire material had already been studied over a lengthy period by the team, which therefore had a solid foundation of knowledge for the development of the film. They knew all about the properties of this material as well as the required nanotechnology. Professor Cheah said that his team did not make the invention for the sake of winning awards. They simply asked: “How can we do it better?” This thin film doubles the hardness when applied to covers of touch screen devices, giving the same anti-scratch performance as crystal sapphire but cutting the production costs by half. Moreover, the production of sapphire thin film takes only a day while for crystal sapphire it takes three weeks. Based on this research, Professor Cheah founded a company with a group of physicists and engineers to launch the commercialisation of the technology. Since the first filing of a patent application in 2014, this state-of-the-art technology now possesses 15 patents and has secured funding from investors and the industry in support of continued research. Professor Cheah said this technology has great potential as it can be applied to a wide variety of materials.

The advanced materials that are the focus of Professor Cheah’s research are ones that are specially created or engineered to be superior and more efficient than existing materials, and can used in areas where they could not previously be applied. The resulting materials are highly significant for humankind as they can meet the newly arising needs in the ever-changing world. Professor Cheah is particularly interested in research related to light. His research interests include linear and non-linear optical properties of organic complexes, plasmonic nano-structures, organic and inorganic phosphors and organic electronics. “I always tell my students that it is easy to know whether your experiment is successful or not if you are studying light. It succeeds when there is light!” Because of his interest in light, Professor Cheah invented the organic LED and secured a number of other patents. And as a result of his curiosity about light, he developed a strong interest in butterflies.

“Butterflies have some of the most striking colour displays to be found in nature. They get their colours from two different sources: the pigments on their wings and the reflection of light. In subtropical areas where sunlight is abundant, it is more common for butterflies to make use of sunlight to give them their bright colours.” In order to study how butterflies obtain their colours, Professor Cheah sought specimens of butterflies. Eventually, he asked for help from the Penang Butterfly Farm, which provided him with dead butterflies for dissection. “Butterfly wings are covered by thousands of microscopic scales, split into layers. When light hits these different layers, it is reflected numerous times and creates different colours. The colours can shift as you move around and watch it from different angles. It’s really fascinating!” In the same way that we marvel at the wonders of nature, we have to admire Professor Cheah’s amazing discovery. Professor Cheah and his team published the world’s first study on the structural colouration of butterflies in a journal of The Optical Society of America. The underlying principle of this colour structure could be applied in the clothing industry. As a result, garments that change colour may soon become a reality. “Research on advanced materials requires broad interdisciplinary knowledge. Researchers need to explore the laws of nature from the angles of physics, biology, chemistry, and so on, before developing materials that can suit current needs,” said Professor Cheah. In other words, one must possess a solid academic foundation in order to be a leader in research on advanced materials.

Never Give Up  
Professor Cheah has been achieving breakthroughs and innovations for several decades now. So what is the secret of his success? Professor Cheah said that he had seldom considered this question. Perhaps the answer lies in the fact that his research has always been triggered by his own curiosity, and this means he always perseveres and never gives up easily. Whenever he starts a project, he first sets a goal and then keeps working towards it. “It always takes years to complete a research project. Bottlenecks may occur from time to time. Therefore, a researcher has to be positive and optimistic.” Nobel Laureate in Physics Professor Samuel Chao Chung Ting once visited HKBU and Professor Cheah said he very much agreed with Professor Ting’s views on research, “The result of a research study is always beyond our expectations and hence takes us by surprise.”

Professor Cheah is one of the few academics who have solid industry exposure. After receiving his doctoral degree, he spent 10 years in UK industry, including eight years at Astrium Space aerospace company, working on projects including meteorological satellites and the International Space Station. His industry background has led Professor Cheah to placing great importance on setting goals and reporting on the progress made. Some of his postgraduate students said that Professor Cheah asked them to set a time frame, which could be six months, a year or even three years, and show how they planned to achieve their goal. Subsequently they had to report their progress and findings on a regular basis. In addition, his industry experience has enabled Professor Cheah to come up with a host of creative ideas and unique viewpoints which help his team to apply or commercialise their research findings. Over the years, Professor Cheah’s distinguished scholarly work has secured over 40 grants from the Research Grants Council, the Innovative and Technology Commission, the National Natural Science Foundation of China, the Croucher Foundation, Mr. Allan Kwong and from industry.

Grateful for Donor’s recognition
Last year, Professor Cheah was appointed Dr. Elizabeth K.S. Law Endowed Chair of Advanced Materials. He said it was a great honour to receive this title. “Of course, students do not understand what a Chair Professor means,” he said. “In academia, becoming a Chair Professor implies that you have made outstanding achievements in your field. The views you express on behalf of the University carry weight.”  Professor Cheah also indicated that sometimes it was difficult, if not impossible, to foresee the application of research projects when launching them. As a result, it is difficult to secure sufficient financial resources for such projects. Therefore, the endowment from Dr. Elizabeth Law can support explorative research that allows ideas to germinate. Professor Cheah said that as the Endowed Chair of Advanced Materials, in the short term he would like to apply the Sapphire thin film to more materials such as plastic. In the long term, he would like to develop a hybrid of inorganic and organic materials that are environmentally friendly, plus electronics that are wearable.

Professor Cheah expressed his heartfelt thanks to Dr. Elizabeth Law for making this endowment possible, “Dr Law’s support is great recognition for the research work at HKBU!” The University is known for its limited space and resources. For example, the Cha Chi-ming Science Tower has been in use for over half a century. The University is currently planning its redevelopment. Nonetheless, in spite of such limitations, HKBU’s research has managed to remain at the cutting edge in global terms. In this regard, Professor Cheah comments positively: “The worst time is over!” He also sees the positive side of limitations such as insufficient laboratory space. “Because of this, students have to think thoroughly and rigorously before doing any experiment and carry it out efficiently because they have to take turns using the laboratory. This results in virtuous competition. In fact, our researchers have a very strong team spirit. They always support and encourage each other.”

Professor Cheah often goes hiking with his students. According to his students, Professor Cheah walks so fast it is almost as if he is running! Everyone who is familiar with Professor Cheah knows that he also practises a great deal to master the more difficult tai chi moves or yoga poses. It must be these qualities of perseverance and endurance that have made him such a world-class scholar, one who constantly achieves breakthroughs and scales ever new heights of success in his research.

*This interview was published in 2017. The endowed professorship bestowed upon Professor Cheah Kok Wai was renamed as Dr. Elizabeth K.S. Law Endowed Professor in Advanced Materials in 2020.