This is the final part of a three-part series on micro-electromechanical systems (MEMS) sensor technology. In the first part, a general introduction to MEMS sensing was given including the underlying principles . Biomedical MEMS sensors were described and the principles of bio-sensing in a typical set of biologically inspired sensors were presented. The second part discussed mechanical sensors and their applications . Some important issues of MEMS sensors were addressed, including the need to compensate for environmental effects, the Casimir effect, harvesting of energy for self-powered sensors, and the subject of sensor selection.