A chemical micropump actuated by self-oscillating polymer gel

We demonstrated a self-driven chemical micropump powered by self-oscillating motions of synthetic polymer gel converting chemical energy into displacements of a thin polydimethylsiloxane (PDMS) sheet to produce a directional flow via micro check valves. The gel oscillations induced by the oscillatory Belousov-Zhabotinsky (BZ) reaction generate large volume change. To effectively exploit this volume change, gel bars were used as drivers. They were sandwiched by a fixed cover glass and a push-bar to communicate the expanding (pushing) force of the gel bars to the pumping chamber. At 25 °C, this gel micropump generated a 0.07 mN stroke force and a 0.28 μL/min positive net flow in the microchannel. Additionally, the flow rate of this gel micropump was increased as the temperature was raised from 20 to 30 °C. Compared to existing chemical micropumps, this gel-based micropump provides advantages of self-oscillating property, easy refueling and thermal controllability. This gel-based soft micropump would be used as wearable or medical devices exploiting the flexibility and quietness.