Fabrication of Electrothermal Microgripper based on Through-Mask Electrochemical Micromachining

The demand for electrothermal microgrippers is gradually growing in various fields. However, the current processing technology is difficult to be compatible with low cost and high efficiency. For this reason, a through-mask electrochemical micromachining (TMEMM) method to fabricate electrothermal microgrippers is proposed in this paper. This approach combines surface acoustic waves (SAW) with induction electrode through-mask electrochemical micromachining (IETMEMM). The comparative analysis of four methods (TMEMM, IETMEMM, SAW-TMEMM, SAW-IETMEMM) demonstrates the critical role of SAW in enhancing blind-hole localization. It emphasizes IETMEMM's superiority in through-hole processing. Then, the process parameter experiments are conducted based on this basis and the preferred parameters were as follows: 6 W/cm² SAW power density, 1.7 MHz frequency, inclined incidence direction, 1 A current and 100% duty cycle. Eventually, a 50 μm-thick stainless steel electrothermal microgripper was successfully fabricated. It has a minimum line width of 28.4 μm. Total processing time is only 22 s. This approach demonstrates both high efficiency and low cost based on a certain accuracy. The present study offers a novel approach to the process of microgrippers.