Fabrication of micro rotary encoder for robot finger and precision machines

点击翻译按钮获取中文摘要

In this project, in order to fabricate the grating patterns of encoder on metal rod surface by lithography, a resist spray method and a pattern transfer technique were proposed. Uniform resist film was coated even on a rough surface. The pattern on the conventional planer mask was transferred to the cylindrical surface by the newly proposed technique, in which mask translation and rod rotation were precisely controlled. Therefore, the pattern ends were connected precisely. The 40 μm pitch grating pattern was transferred on the stainless rod of 3 mm in diameter. Etching the metal surface, the grating pattern was formed on the metal rod.As to the sensor part of the encoder, index grating, photo-detector, light source were integrated by silicon micromachining. The index grating was consisted of Si grids. The photodiodes were installed on the Si grids of the index grating. The light source suited for the encoder was spatially fabricated of GaAs substrate. By stacking those components, a micro optical encoder was integrated.In the application to the robot finger, an experimental setup for the finger was fabricated, in which the proposed encoder was installed. Although the encoders installed in the setup were small, the encoder signal was precise enough for the purpose. From those experimental results, most of the purpose of the project was accomplished.