Spark-assisted micro machining of glass

Abstract

In this research, a new method for micro machining of glass was developed. The process is called spark-assisted micro machining (SAMM), which is a hybrid process of electrochemical discharge machining (ECDM) and mechanical squeezing. ECDM is known as an effective method in micro machining of glass

however, the low material removal rate and the poor surface quality make it not become a common selection in micro machining of glass. In ECDM, glass material was removed by evaporation and etching of glass thanks to the heat from ECDM sparks. Therefore, the ECDM craters are always available on the machined structures. In the novel method, SAMM, the glass material is mainly removed by a mechanical squeezing process by which the surface quality is dramatically improved. In SAMM process, ECDM sparks play a role as a heat source which elevates the temperature of the local machining zone. The glass material at the local machining zone is softened. The softened glass is, then, removed by squeezing by the micro tool. In this paper, the mechanism of SAMM was investigated and machining conditions were studied by which suitable conditions were found. Many 2D and 3D structures such as micro channels, micro wall arrays, micro column array, micro towers and micro reservoirs were fabricated in Pyrex glass to show the performance of the SAMM.