|演講公告-Dr. Say Hwa Tan’s talk on June. 3. 2016|
AC electro-hydrodynamic in microfluidics
Dr Say Hwa Tan, BEng, MEng, Dr. rer.nat,
Griffith University Post-Doctoral Fellow
Winner of Tan Kah Kee Postgraduate Award 2012
Winner of Tan Kah Kee Young Inventor Award 2014
AC electro-hydrodynamic in microfluidics has attracted enormous attention due to the prospects in many different applications. First, we demonstrate the control of droplet sizes by an ac voltage applied across microelectrodes patterned around a flow-focusing junction. The electrodes do not come in contact with the fluids to avoid electrochemical effects. We found several regimes of droplet production in electric fields, controlled by the connection of the chip, the conductivity of the dispersed phase and the frequency of the applied field. Second, using the interplay of electric field and hydrodynamics in microfluidic devices, well controlled frequency patterns corresponding to musical tracks are generated in real time using our microfluidic jukebox. Lastly, we show the droplet deformation induced by an AC electric field in droplet-based microfluidics. It is found that the deformation of the droplets becomes stronger with increasing electric field intensity and frequency.
Dr Say Hwa Tan is a Griffith University Post-doctoral Fellow in Queensland Micro-and Nanotechnology Centre, Griffith University, Australia. He received his PhD in 2014 from the Georg-August-Universität Göttingen and Max Planck Institute for dynamics and self-organization (MPI-DS), Germany. During his PhD, he patented a new technology to actively control the size of microdroplets using an AC electric field. A Microfluidic Jukebox was developed using the technology. His research has pioneered different approaches to manipulate droplets and bubbles using thermal, magnetic, acoustic and electric energy. Dr. Tan has published over 20 journal papers, 2 patents and 1 book chapter on droplet microfluidics.