The group which includes RIKEN’s QBiC Center in Kobe and Tokai Rubber Co. developed a bio-microdevise based on a proprietary electric elastomer which, on applying voltage, acts like a valve at high speed.

Yo TANAKA et al., Sensors and Actuators B Chemical, July 31, 2013, https://dx.doi.org/10.1016/j.snb.2013.04.025