This book presents an unconventional and largely unknown technology, which is able to micro-machine at relatively low cost glass, polymers and other materials. This process is called Spark Assisted Chemical Engraving (SACE), or Electro Chemical Discharge Machining (ECDM). First presented in 1968 in Japan by Kurafuji and Suda, this technology was studied essentially in the academic world and mainly applied for micro-fluidic devices. This book explains the fundamentals of SACE, promotes the technology, and encourages researchers and engineers from industry to use it for their specific applications. Therefore, the book, after presenting in details the fundaments of SACE (in particular the Electrochemical Discharges), deals mainly with practical aspects of implementing the machining technology. The book is written so that researchers from fields other than micro-technology (e.g., from life science) will be able to build a simple machining set-up, together with his mechanical work-shop, for individual needs.

Rolf Wuumlet;thrich is an Assistant Professor in the Department of Mechanical and Industrial Engineering at Concordia University, Montreal. His research includes: micromachining of glass and ceramics by non-traditional processes (fundamental aspects, modeling and simulation); development of microdevices for microfluidic, Lab on a Chip, microfuel cells and biosensors; and fabrication of nano-particles using electrochemical discharges. Dr. Wuumlet;thrich has published over 50 peer-reviewed journal and conference papers in his research field of micromachining of glass using electrochemical discharges, and has been invited to give keynotes in international conferences.

Series Editor Preface The possibility of modifying materials using electrical discharges has fascinated mankind ever since he observed the results of lightning striking objects in nature. We do not, of course, know when the first observation took place, but we may be reasonably sure that it was a sufficiently long time ago that many millennia had to pass before electricity was "tamed", and subsequently put to work modifying materials in a systematic, "scientific" way-as exemplified by Humphrey Davy's electrolysing common salt to produce metallic sodium at the Royal Institution in London. But these are essentially faradaic processes (named after Davy's erstwhile assistant Michael Faraday), and such processes are also used extensively today for (micro) machining, as exemplified by electrochemical machining (ECM). They are relatively well known, and are applicable to conducting workpieces. Far less well known is the technology of what is now called spark-assisted chemical engraving (SACE), in which the workpiece is merely placed in the close vicinity of the pointed working electrode, and is eroded by sparks jumping across the gas bubbles that develop around the electrode to reach the electrolyte in which everything is immersed, the circuit being completed by the presence of a large counterelectrode. This technology can therefore be equally well used for workpieces made from nonconducting materials such as glass, traditionally difficult to machine, especially at the precision micro level needed for such applications as microfluidic mixers and reactors. The development of attractive machining technologies such as SACE is in itself likely to play a decisive part in the growth of microfluidics-based methods in chemical processing and medical diagnostics, to name just two important areas of application. Since, as the author very correctly points out, knowledge about nonfaradaic electrochemical machining methods is presently remarkably scanty within the microsystems community, this book is conceived as a comprehensive treatise, covering the entire field, starting with a lucid explanation of the physico-chemical fundamentals, and ending with a thorough discussion of the practical questions likely to be asked, and an authoritative exposition of the means to their resolution. I therefore anticipate that this book will significantly contribute to enabling the rapid growth of micromachining of nonconducting materials, for which there is tremendous hitherto unexploited potential.