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Updated: Feb 3, 2026
Polymeric Microneedle Array Fabrication by Photolithography
Published on: November 17, 2015
Fabrication of Hexagonal Microlens Arrays on Single-Crystal Silicon Using the Tool-Servo Driven Segment Turning
1Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. mukaida@keio.jp.
Abstract:
Single-crystal silicon microlens arrays are increasingly required in advanced infrared optics. In this study, the authors attempted to fabricate hexagonal microlens arrays, which offer high optical efficiency, on a single-crystal silicon wafer using diamond turning. A tool-servo driven segment turning method was proposed to reduce the dynamic error of the machine tool induced by lenslet edges during lens array cutting. From the results of both cutting experiments and theoretical analysis of the machine tool dynamic error, it was demonstrated that the segment turning method reduced significantly the dynamic errors and led to high form accuracy. As a result, sharp edges among the lenslets were generated precisely and microlens arrays with a form error of ~300 nm peak-to-valley and surface roughness of ~5 nmSa, which meets the requirements of infrared optical systems, were successfully fabricated. The subsurface damage, such as the amorphization of silicon, caused by machining was also reduced.
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