Electrochemistry means all processes of ions or molecules at charged interfaces, that is, faradaic as well as electroless processes. They take place usually at solid/liquid interfaces, but liquid/liquid interfaces may be included, too. Micro limits the systems and processes to the range bellow 1 mm in all three dimensions x, y, z.

Micro-electrochemistry is a fast growing part of electrochemistry forming interdisciplinary bridges to science and medicine (Figure). Moreover, it finds growing application in various field of technology. The new subject of electrochemical microsystems includes and extends the fundamental knowledge of electrochemistry, but in difference to fundamental science, it emphasizes the technological applications. Special development in corrosion research, microelectronics and biology have characterized this insulation of highly specialized fields of engineers and scientists in recent years. 

 Electrochemical Microsystem Technologies, (New Trends in Electrochemical Technology), J. W. Schultze, T. Osaka, M. Datta, CRC Press, P 4.