Pneumatically driven microcage for microbe manipulation in a biological liquid environment

This paper describes the design, fabrication, and force analysis of a pneumatically driven microcage. Pneumatic actuation, suitable to function in a wide range of environments, is especially useful for operation in a small liquid space. The capture of single motile microbes (Volvox and Stentor ~ 400 [micro]m) in aqueous environments is demonstrated with the microcage. The setup for the capture experiment includes a visualization scheme, a robotic micropositioner, and an electropneumatic control system that facilitates the underwater tracking of the moving microbes and the operation of the microcage for subsequent capture. Index Terms--Microelectromechanical systems (MEMS), pneumatic actuation, residual stress, three-dimensional (3-D) structure.