Electro-chemical Discharge Machining

Micro fluidic and lab on-chip devices are gaining extreme popularity for the biotechnology industries, due to the small size, fast analysis times, and accuracy. However, current fabrication methods for such devices require access to micro fabrication clean rooms, well controlled environments, and expensive equipment. In this project, we explore a new method of micro-machining, namely electro-chemical discharge machining (ECDM), with the goal of creating robust, inexpensive micro scale fluidic channels for bio-analytical devices. ECDM utilizes strong electric fields and chemical reactions to etch glass substrates and is performed by submerging the sample substrate in high concentration Sodium Hydroxide (NaOH) solution and applying a 60V DC potential between the electrolyte solution and a tool electrode a located a few micrometers above the target etch site. Previous work by [1] has shown that conical and spherical through-holes can be etched using a needle tip tool electrode. The goal of this project is to create a stable platform for repeatable ECDM micro channel etching with razorblade tool electrodes. To date, I have used the computer aided design program, Solid Works, to create a 3D design and engineering drawings for a robust mechanism to hold a razorblade as the tool electrode. Preliminary results show that ECDM with a razorblade tool electrode can etch channels. Further experiments will be performed to determine whether the channels etched by ECDM are a viable alternative to micro fabrication for bio-analytical applications.

[1] West, J.; Jadhav, A. ECDM methods for fluidic interfacing through thin glass substrates and the formation of spherical microcavities, 2007, J. Micromech. Microeng. 17 403-409