A Low-Temperature Thermopneumatic Gas Bubble Valve

We introduce a novel type of actuation for microvalves, in which a trapped air bubble functions as the thermally controlled volume displacing element. The pressure of the trapped air pocket is controlled thermally using a resistive heater. The volume displacement is determined by the liquid surface tension and the valve geometry. A fully functional demonstrator device was successfully fabricated and tested. The absence of moving mechanical parts, the electrical control of the valve, and the limited required actuation temperature make the actuator suitable for control of LSI fluidic networking in biotechnical applications.