A micro cycloid-gear system fabricated by multi-exposure LIGA technique

In this paper, a prototype of 2 mm-diameter micro-cycloid gear system fabri cated by the multi-exposure LIGA technique is presented. The gear system is composed of a casing and three vertically stacked disks and gears. Each pa rt consists of three different levels. The first level, 40 mu m high, was f abricated by UV-lithography, and the second as well as the third level, 195 mu m and 250 mu m high respectively, were processed by aligned deep X-ray lithography (DXL). The alignment error between two DXL-processed layers has been measured to be within +/-5 mu m range. As a result of the height cont rol process, the deviation of structural. height has been maintained within +/-3 mu m range for the UV-lithography-processed structures, and +/-10 mu m for the DXL-processed structures. Preliminary tests of gear assembly have been implemented with 125 mu m-diameter commercially available glass fiber , and the further efforts are being carried out.