Spring 1997
Dr. D.M. Allen and T.T. Chen, Cranfield University
This paper describes the manufacture of miniature cantilevers from free-standing, 10 µm thick sputtered NiTi SMA films and double-beam devices from similar films deposited on alumina, coated with sputtered noble metal, using the technique of electrochemical micromachining. This technique employes standard photoresist processing but with dissolution of the alloy achieved by an anodic process in an electrolytic cell using a non-aqueous electrolyte of 5% sulphuric acid in methanol to etch the devices. .The etch rate depends directly on the anodic current density but the problem of determining the exact etching time to achieve a vertical edge profile on the devices still presents a challenge.
