Prof. Jiwang Yan, Keio University, Japan

Title:

Ultraprecision machining for micro IR optics

Abstract

Infrared (IR) optics are important in thermal imaging and night vision systems which are widely used for temperature measurement, rescue and security purposes. However, the production cost of IR optics is very high, which is currently a major drawback to industrial applications. In this talk, research outcomes of the speaker's group on ultraprecision fabrication of IR micro optics will be highlighted. Two examples will be given. First, a tool servo-driven diamond turning process for manufacturing IR micro lens array will be introduced. This method was successful to generate micro lens arrays on a single-crystal silicon wafer in a ductile mode. Second, a hybrid structure of single-crystal silicon and high-density polyethylene (HDPE) was developed for IR lenses by using precision press molding. A ~100 micron thick HDPE film was used to laminate a silicon wafer and their interface was directly bonded by the silane cross-link. The HDPE film is easy to be hot-embossed to form three-dimensional surface microstructures such as Fresnel lenses, and the silicon wafer provides a high stiffness for the hybrid substrate. The imaging test result shows that the hybrid substrate is capable to produce acceptable image quality both in night vision and thermography, demonstrating that the developed hybrid substrate is a promising alternative substrate material for IR lenses.

Biography

Professor Jiwang Yan obtained his Ph.D. from Tohoku University, Japan in 2000 and is currently a professor of Mechanical Engineering at Keio University, Japan (2012-now), leading the Laboratory for Precision Machining and Nano Processing. He is also a specially-appointed professor (adjunct) at Tokyo Institute of Technology, Japan (2017-now) and a Leverhulme Visiting Professor at The University of Manchester, UK (2018-2019). His research areas include ultraprecision machining, micro manufacturing, nanomaterial processing, and nanomechanics. He has led more than 20 nationally funded projects and over 60 joint research projects with industry as a principal investigator. He has authored/co-authored 200+ peer-refereed journal papers and given 100+ keynote/invited talks at international conferences and research institutions. He has received 30+ awards for his contribution in the manufacturing area, and his research results have been featured by several major newspapers and media in Japan for 20+ times. He serves on editorial boards of 11 international journals, and serves as the Editor-in-Chief for book projects including the Springer Micro and Nano Fabrication Technology.