Nastic Acuators

Nastic actuators are a new type of electroactive polymer (EAP) based on hydraulics:  a fluid is pumped by electroosmosis within microchannels in compliant material from one place to another.  The hydraulic pressure causes the compliant material to deform.

Post-doc Menake Piyasena, with the assistance of undergraduates Robert Newby and Tom Miller, has developed a working demonstration device on the cm-scale made from PDMS with water as the fluid.  The expansion and collapse occur within seconds, with membrane deflections of hundreds of micrometers.  Upon optimization, high forces should be possible.

The thin membrane above the expansion chamber deflects upward (see right), and the one above the supply chamber downward, upon application of the electric field.

For further information, see:

M. E. Piyasena, R. Newby, T. J. Miller, B. Shapiro, and E. Smela, "Nastic actuators: electroosmotically driven microfluidic cells," Sens. Act. B, 141, 263-69 (2009).