Small, soft and safe micro-machines for biomedical applications

This paper deals with small, soft and safe micro-machines using MEMS technology for machining, polymers as main materials, and pneumatic pressure for driving principle. As a typical example of small, soft and safe micro-machines, a pneumatic balloon actuator is introduced along their developing literature. Thin and soft structure can generate force of several hundred mN or more by pressure of several hundred kPa. Various biomedical applications of the pneumatic balloon actuator are presented especially for minimally invasive medicine, from neuro interface to endoscopic instruments. Recent work on cellular manipulation for tissue engineering is also reported. Suction devices using negative pressure are presented as well as micro-machines using positive pressure. The suction device fixes and stabilizes a micro device such as a sensor chip on a beating organ. We discuss attractive features and possibilities of small, soft and safe micro-machines in this paper.