11420E500100 Seminar

TOPIC
▸　Overview of Our Continuous Development in Beam Steering and Imaging Systems for Biomedical, THz, and Hyperspectral Applications

❝　To reduce tissue trauma before and during surgical procedures, our research has focused on developing advanced technologies for integrated 2D scanning imaging systems in endoscopy and optical coherence tomography. These core beam-steering and scanning technologies have also been extended to other biomedical optical imaging systems. More recently, this effort has expanded into the Terahertz (THz) regime for non-destructive biological and tissue imaging applications.
❝　Conventional flexible endoscopes are designed to minimize trauma, but their field of view remains fundamentally limited by the optical aperture, whether based on fiber bundles or miniature cameras. To address this limitation, we have demonstrated a mechanically resonant single-pixel waveguide cantilever scanner for image acquisition using microelectromechanical systems (MEMS) techniques. This approach enables a compact imaging platform that achieves a field of view and resolution comparable to conventional systems while significantly reducing system size, and integrates the waveguide, light source, actuation, and detection elements into a unified scanning platform. An improved version has further reduced fabrication complexity and improved scanning performance by leveraging nonlinear vibration dynamics and non-semiconductor substrate materials.
❝　To further reduce mechanical contact and associated tissue disturbance, we developed a non-mechanical scanning architecture based on integrated polymer lens arrays, gratings, and prism-based beam steering elements. This system utilizes an electro-optic (EO) medium to achieve beam collimation and deflection without mechanical resonance. A specially engineered EO polymer with low absorption in the visible spectrum and high optical nonlinearity was developed using micro- and nanofabrication techniques to realize the required optical components.
❝　For non-destructive tissue imaging and biopsy applications, we are developing a portable THz beam-steering system based on gradient metamaterials. In contrast to conventional free-space electromagnetic steering systems, which are typically bulky and limited in spatial resolution, our approach integrates tunable metamaterials with electro-optic components to enable compact THz beam control. The system performs scanning over the region of interest to reconstruct THz images, achieving good steering angles, strong beam confinement, and subwavelength beam sizes in both far field and near field application.
❝　In this presentation, we will discuss the underlying principles, applications, and experimental demonstrations of image acquisition and beam steering across these three approaches. We will also provide an overview of our laboratory research, highlighting past, current, and future efforts in the development of amorphous and metamorphic materials and structures for electromagnetic applications.　❞

SPEAKER
▸　Prof. Wei-Chih Wang
▸　Department of Power Mechanical Engineering, National Tsing Hua University 

Bio sketch:
❝　Dr. Wei-Chih Wang is currently a Professor in Power Mechanical Engineering and the Institute of Nanoengineering and Microsystems at the National Tsing Hua University. He is also an affiliated Professor in the Department of Mechanical Engineering and the Department of Electrical and Computer Engineering at the University of Washington. He received his degree in electrical engineering from the University of Washington in 1996 and completed a postdoctoral fellowship for a DARPA-funded piezoelectric MEMS project at the University of Hawaii in 1996-1997.
❝　Dr. Wang has authored or co-authored over 260 technical publications and holds more than 50 US and PCT patents. His research has focused on developing polymer-based microsensors and actuators for industrial and biomedical applications. In recent years, he has expanded his work to include research on THz, IR, and visible band 3-D metamaterials, as well as electromagnetic and electro-active polymer material study. He has also established a new field of study called amorphous and metamorphous structure and material.
❝　Dr. Wang is currently a Fellow of SPIE, a member of IEEE, ECS, Eta Kappa Nu, and NIH review committee. He serves as an associate editor and a member of the editorial board for the International Journal of Optomechatronics and the Sensors & Transducers Journal. He has also served on program committees for SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, as well as the International Symposium on Optomechatronics Technologies (ISOT) since 2003 and 2009, respectively. Additionally, he has served as general conference Chair for the International Symposium on Optomechatronics Technologies conference in Jeju, Korea in 2013 and Seattle, USA in 2014.　❞

TIME
▸　2026/05/12 (TUE) 13:20 ~ 15:10

VENUE
▸　Classroom 201, Engineering Building 1