Mechanical Engineering Seminar


Innovating Optical Manipulation and Measurement of Nanomaterials


Dr. Jigang Li


University of California, Berkeley,


Monday, March 25, 2024 at 3:30:00 PM   


GTMI Building, Room Auditorium


Dr. Zhuomin Zhang


The exploitation of light has enabled key breakthroughs in many areas, including energy, manufacturing, imaging and sensing, communications, and biology. Continuing development of these fields for greater impact necessitates a comprehensive understanding of light-matter interactions across diverse time and length scales for more efficient harnessing of light. In this seminar, I will present novel optical technologies for versatile manipulation of nanomaterials and advanced measurement with high spatiotemporal resolution. First, optothermal manipulation techniques are developed to overcome the limitations of Nobel-prize-winning optical tweezers. Specifically, optorefrigerative tweezers exploit laser cooling and thermophoresis to mitigate common optical heating challenges, providing a safe way to measure cells and biomolecules. In addition, the capability of optical tweezers is extended from fluid environments to solid surfaces, enabling solid-phase optical assembly and nanomotors for next-generation lab-on-a-chip systems. Next, I will show the implementation of an ultrafast optical nanoscopy by integrating pump-probe optics with near-field imaging. This tool exhibits promising potential to reveal intriguing carrier dynamics and energy transport in various functional materials with nanoscale heterogeneity. Along the way, I will discuss the potential of these optical approaches to provide solutions to disease diagnosis, nanomanufacturing, and energy-efficient optoelectronic devices.


Dr. Jingang Li is a postdoctoral researcher in the Department of Mechanical Engineering at University of California, Berkeley. Dr. Li received his Ph.D. in materials science and engineering from The University of Texas at Austin and his B.Sc. in applied physics from University of Science and Technology of China. His research aims to understand the fundamentals of light-matter interactions and develop new tools for multiscale measurement and diagnosis to tackle critical technological challenges in electronics, materials science, energy, and bioengineering. His work has been recognized by MRS Graduate Student Award, Rising Stars in Mechanical Engineering, and Ben Streetman Prize. For more information, see