Professor Wang Zuankai of City University of Hong Kong (CityU) won the 2020 Xplorer Prize organised by the Tencent Foundation for his fundamental research on water energy harvesting. He will continue his research on energy harvesting as well as nature-inspired engineering with the awarded grant.

Established since 2019, the Xplorer Prize is awarded to a maximum of 50 Chinese young scientists each year. The nomination was extended to young scientists from Hong Kong and Macau this year. Winners were announced earlier and three winners are from Hong Kong, with Professor Wang being one of them.

 

Professor Wang feels honoured to win the prize. “I’m very grateful to the University community for their support, which enabled me to conduct research that I enjoy a lot. My gratitude also goes to Tencent, whose investment in science and future is visionary. Scientific research has no boundary. I hope this prize can inspire young scholars to explore further,” he said.

Technology breakthrough in water energy harvesting

Professor Wang, concurrently Associate Dean (Internationalisation and Industry Engagement) in the College of Engineering and Professor in the Department of Mechanical Engineering and the Department of Materials Science and Engineering, has achieved research breakthroughs in the areas of nature-inspired engineering, thermal fluid dynamics and energy harvesting.

Titled “A universal strategy for efficient water energy harvesting: from fundamental understanding to practical applications”, Professor Wang’s winning project falls into the category of “Advanced Manufacturing”. This project aims at exploring the basic principles underpinning efficient energy generation rendered by combining super-slippery lubricant surfaces with bulk effect structure; engineering durable dielectric materials that are capable of shedding liquid rapidly, building up high charge density on the surface, and applying to various harsh conditions; as well as leveraging the synergy from super-slippery surfaces and bulk effect structure to develop efficient energy harvesting devices applicable to a wide range of environmental conditions, energy sources and formats, interfaces or scales.

He plans to use dielectric materials, including a variety of fluorinated polymers and lubricants, to develop super-slippery surfaces that can be used in different environments and climates. These surfaces can promote the rapid detachment of liquid, thereby achieving surface charge generation, transfer and even high-density storage, and significantly improve the durability and stability of the device in different environments.

Super-slippery lubricant material inspired by pitcher plants

In 2019, Professor Wang’s research team collaborated with fellow researchers from the University of Science and Technology of China, East China Normal University, and the University of Nebraska-Lincoln, in developing a new energy harvesting device (SLIPS-TENG) by combining slippery lubricant-impregnated porous surface (SLIPS) technology with a triboelectric nanogenerator (TENG).

The SLIPS technology was invented by scientists at Harvard University in 2011, inspired by pitcher plants. With this technology, a liquid surface is formed by infusing liquid lubricant with low surface tension into solid materials.

 “We have successfully combined two seemingly different technologies, SLIPS and TENG, and achieved triboelectricity generation in a liquid-liquid interface. From a broader perspective, the marriage of SLIPS with TENG technologies can provide a paradigm shift in the design of blue energy devices with longer life and enhanced properties,” said Professor Wang when the research was published in National Science Review, back in 2019.

Even a drop of water can generate electricity

Professor Wang also proposed to use an electrode design similar to a transistor structure to transform the traditional surface effect into a more efficient bulk effect, and as a result, both the power density and energy conversion efficiency were highly enhanced. The reversible transfer between the charge and the electrodes were also achieved, ensuring the stability of long-term output.

Similar designs have been applied to the droplet-based electricity generator (DEG) that he developed jointly with the research team comprising Professor Zeng Xiao Cheng from University of Nebraska-Lincoln, and Professor Wang Zhong Lin, Founding Director and Chief Scientist at Beijing Institute of Nanoenergy and Nanosystems of Chinese Academy of Sciences (CAS).

The DEG they developed is featured with a field-effect transistor (FET)-like structure, which allows for high energy-conversion efficiency. The instantaneous power density is increased by thousands times compared to its counterparts without FET-like structure. 

Their research findings showed that a drop of 100 microlitres (1 microlitre = one-millionth litre) of water released from a height of 15 cm could generate a voltage of over 140V. And the power generated could light up 100 small LED light bulbs. The breakthrough of this research would facilitate hydropower researches and help in dealing with the energy crisis. Their findings were published in the highly prestigious scientific journal Nature in February 2020.

Professor Wang obtained his bachelor's degree in mechanical engineering at Jilin University in 2000. He received the master’s degree in microelectronics from the Shanghai Institute of Microsystem and Information Technology of CAS in 2003. In 2008, he obtained the PhD degree in mechanical engineering from Rensselaer Polytechnic Institute, USA. He later continued his study as a postdoc in biomedical engineering at Columbia University, USA. He joined CityU in September 2009.

Professor Wang is a Chang Jiang Chair Professor selected by the Ministry of Education, and a Fellow of International Society of Bionic Engineering (ISBE). In 2016, he became the first recipient from Hong Kong to win the Outstanding Youth Award conferred by ISBE. He won CityU’s President’s Award consecutively in 2016 and 2017. He also received CityU’s Outstanding Research Award in 2017. He is one of the nine outstanding young researchers being selected by the World Cultural Council in 2018.

The Xplorer Prize is funded by the Tencent Foundation and initiated by Ma Huateng, Chairman and Chief Executive Officer of Tencent and founder of the Tencent Foundation, as well as well-known scientists such as Yang Chen Ning. Established since 2019, the Xplorer Prize aims to support young scientists working in areas of fundamental science and cutting-edge technologies. Each winner will get a sum of RMB 3 million over five years.