【Seminar on 2019/12/3 (Week 12)】
Speaker: Distinguished Professor Ping-Hei Chen of National Taiwan University
Title： Evaporation of water droplets and pool boiling heat transfer on plain and silica-coated copper surfaces textured with picosecond laser
Date: 2019/12/3 (Thu) 3:30 pm - 5:20 pm
Location: Engineering 5 Building B1 International Conference Hall
This study presents a hybrid surface modification method involving chemical bath deposition and ultrafast laser. First, the selected copper substrates are modified using the sol-gel method through dip coating. Subsequently, the coated copper surfaces are irradiated with a picosecond laser. After laser texturing, bumpy structures are formed, and SiO2 nanoparticles can be sintered on the surfaces. Thus, the original hydrophilicity can be maintained, and the surface roughness can be enhanced simultaneously. By using this hybrid modification method, both homogeneous and heterogeneous surfaces with high-precision patterns can be obtained. Water droplet evaporation on such a homogeneous flat surface and water pool boiling on a cylindrical surface with biphilic patterns are investigated. Enhancements of evaporation and pool boiling heat transfer with such a hybrid surface modification method are presented.
About Speaker: Prof. Ping-Hei Chen received his bachelor degree in mechanical engineering from National Taiwan University in 1980. After completing his military service, he went to U. of Minnesota for his graduate study. He received his master and Ph. D. degree in mechanical engineering from U. of Minnesota in 1984 and 1988, respectively.
In 1988, he joined the Department of Mechanical Engineering of National Taiwan University as an associate professor. He was promoted to full professor in 1996, and serve as the vice-chairman of the Department from 1996 to 1998, and as the chairman from 1998 to 2001. From 2014-2017, he was appointed as the director of Tjing-Ling Industry Research Institute, National Taiwan University. He has published 172 journal papers and been issued 17 patents. His excellent achievement in sensor-related research is highly regarded in the field and he has received numerous research awards, such as three distinguish research awards from Ministry of Science and Technology, fellowship from ASME, and distinguished professorship from National Taiwan University. From 2011-2012, he also serves as the Executive Secretary of the Office of Science and Technology, the task force to support the Board of Science and Technology of the Executive Yuan to review national science and technology policy guidelines and resource management. His major research areas are in MEMS, Biomedical devices, nanotechnology, energy harvesting chips, highly efficient energy systems, and sensors.
In the past 14 years, Dr. Chen has overseen several programs that focus on mentoring, incubating, and sponsoring start-up teams from universities in Taiwan. He is currently the director of TRUST-U program that manages a 130-million-USD fund to provide financial support to university startup teams from 2017 to 2020. The funding of TRUST-U program is supported by Ministry of Science and Technology in Taiwan. Since its inception, the program has invested in 103 university startup teams, of which 23 teams have successfully raised over 70 million US dollars to set up their own companies.