Applications of Biologically Inspired Membranes

The focus of this paper is projection of the performance of nastic actuators under conditions of variable stimulus with particular emphasis on pharmaceutical applications. The nastic actuator concept considered here employs controlled transport of charge and fluid across a selectively permeable membrane to achieve bulk deformation, similar to nastic movements in the plant kingdom. These membranes may utilize biological ion pumps, ion channels, and/or ion exchangers to transport fluid and ions and thereby expand/contract a phase separated inclusion. Studies to date have focused pH gradients or the spontaneous introduction of ATP chemical energy as the triggers for actuator response. In this effort the physics of the nastic actuator response under variable stimulus is considered. In addition, the possibility of controlled bursting of the nastic inclusions for vaccine delivery is explored.