Chia-Yuan Chen is a Professor from the Department of Mechanical Engineering at National Cheng Kung University (NCKU) in Taiwan. He served as the Associate Vice President for International Affairs and the Director of International Relations Division Office affiliated with NCKU for international collaboration on the academic level from 2017-2020 where he directly/indirectly facilitated over 20 official agreements of NCKU with counterpart universities in Europe, North America, and Asia. He received his Ph.D. degree in Biomedical Engineering from Carnegie Mellon University (CMU) in 2012, and his fields of research interests include hemodynamics, flow visualization, computational fluid dynamics, and microfabrication with a focus on practical applications. For his roles in professional services, he served on the Technical Program Committee and the section chair for 2018 IEEE MEMs conference (one of the largest annual events in MEMs fields) as well as the reviewer for more than 30 SCI journals. He was also invited by American Institute of Physics (AIP) publisher serving as a book editor along with several editorial roles including guest/topic editors in major SCI journals. He was the recipient of Ta-You Wu Memorial Award from Ministry of Science and Technology in 2018 (the most prestigious young scholar award in Taiwan), in addition to quite a few outstanding young scholar recognitions in the high-end research domain. As an independently principal investigator he authored 51 scientific papers published in the leading microfluidic/biomedical related journals, with several featured as journal cover, editor’s pick, and annually outstanding papers. In 2022, he was selected as the Fellow of Royal Society of Chemistry for his contribution to the science and technology advancement. 

Research Highlight: original research developed by Prof. Chen and the team over past years is elucidated in the following based on the core concept of biomimetic studies through magnetically actuated artificial cilia and microrobots for microfluidic, developmental biology (zebrafish), and human cardiovascular applications by means of experimental (flow visualization) and numerical assessments.

Research summary:  Inspired by nature, artificial cilia and microrobots now have been created in the laboratory to facilitate flows in microfluidic environments as well as in microcirculation. These artificial cilia and microrobots can be actuated under the influence of external stimuli—such as electric, magnetic, resonance or even light stimuli—and exhibit their capabilities for generating/mixing flows within the microfluidic platforms. Magnetically actuated artificial cilia, for example, are considered as a good alternative, as they require less complex fabrication processes, in addition to their inert property towards biological specimens and easy control with high precision. It was observed that with the optimized configuration, superior mixing can be achieved using these artificial cilia-based microfluidics for a better alternative in lab-on-a-chip applications. The practical applications of artificial cilia/microrobots can be further extended to photodegradation (pollution removal), zebrafish manipulation (new drug screening), catheter navigation with reduced blood damage (stroke and aneurysm treatments) as addressed below.

Specific Aims: Developing and integrating artificial cilia into microfluidic platforms for 3D flow control with multiple functions in biology, biomedicine, and engineering. A comprehensive magnetic coil system compact in size will be further modified to best control the fabricated artificial cilia/microrobots in various test conditions. In addition, a 3D flow visualization technology will be employed to assess the induced flow by artificial cilia actuation to provide physical insights into the effects of fluid-induced mechanical stress contributed by these hair-liked structures as well as for studying blood circulation and zebrafish behaviors in the developmental stages. A new chapter is envisaged to be written through the profound applications using artificial cilia where a high degree of flow control is needed.

(a). To develop biomimetic systems for practical applications in microfluidics, zebrafish tests, and photodegradation: Systematic integration will be achieved to further implement artificial cilia for multi-functioning. First, to provide a higher degree of microscale flow control, the fabrication of magnetically actuated artificial cilia will be remodeled by optimizing the distribution of concentered magnetic particles in the structure of artificial cilia aligning the magnetized directions through a core-shell concept. Secondary, the designed microfluidic platforms will be developed in a handful size and portable for practical applications including the assessment of cardiovascular diseases, sorting of circulating tumor cells, zebrafish sperm activation, and fertilization together with the pollution degradation through artificial cilia agitation. Intensive investigation and discussion will be put into practice to further provide underlying physical and biological insights with the presented designs. Specifically, instantaneous dynamics of artificial cilia will initially be precisely performed to generate flow shear in a well-controlled manner. The fluid-induced shear stress serving as the mechano-signal that can be delivered through the genetic pathway affecting the vasculature of bio-samples on the cellular scale which plays an important role in the regulation on of the blood circulation. The high accuracy of flow shear stress control can also lead to rapid cell separation through balance of the hydrodynamical lift and drag forces. Several successfully examples can be found in applications such as blood purification and cell sorting via microfluidics. A comprehensive characteristic test will be included in the work plan to provide better alternatives tacking problems encountered in the aforementioned areas, and systematic platforms on the basis of artificial cilia will be developed and launched on the commercial market to spark the impact to the biomedical community.

(b). To develop a reliable stereoscopic μPIV (micro-particle image velocimetry) strategy at micro-scale on the experimental arm for high accuracy biological/engineering flow measurements: Accurate measurement of fluid-induced wall shear further sheds light into the role of mechano-transduction in the regulation of human circulation and surrounding flows of aquatic species for pray capturing and feeding. In light of these perspectives, a non-invasive flow quantification method is in high demand to delve into the underlyingly physical phenomena for small scale biological/biomedical and chemical assessments, in additional to the conventionally mechanical investigation. Still, contemporary set-up of µPIV is only available for two-dimensional measurements with several limitations such as a rigid test rig requirement which is not suitable for biological flow applications where the wall compliance is in general a necessary element. The combination of microfluidic designs through a moving wall concept to accommodate the biological activities provides a new alternative for precise flow measurement at microscale. The same technology can be further extended to study human cardiovascular diseases such as aneurysm and atherosclerosis where the mechanical behaviors of the vessel wall plays a major rule in the disease initialization and evolution.    

(c) To improve medical treatments of human cardiovascular disease using artificial cilia mimicking the function of a microcatheter and the associated flow diverters: the maneuverability of a microcatheter tip plays a pivotal role affecting the navigation precision in the vascular network and the success rate of an endovascular surgery. Here a cutting-edge microcatheter tip will be developed to provide a higher degree of motion dynamics with reduced blood damage through an improved catheter tip design originated from the beating concept of natural cilia. A better maneuver with robust actuation through this design can significantly result in a better surgical outcome with less complication occurrence. As a proof of concept shape memory alloy material together with microfabrication technology will be employed in the fabrication of the catheter tip. A fully automatic actuation system will be developed to provide remote and time-dependent manipulation of the developed catheter with instantaneous imaging capability during the surgically steering procedure. This research innovation is envisaged to provide an alternative for a rapid, high precision, and easy to be integrated into the endovascular process for a superior medical surgery. 

(d) : Establish numerical modelling though in-house/commercial codes for 3D verification and validation: setting up numerical alternatives to provide 3D view of hemodynamics for calculating wall shear stress with a high degree accuracy as supporting material for experimental data as well as a design proof.