| Description |
Microfluidics is an emerging field with the potential to develop small, portable lab-on-a-chip equipment. To accomplish this goal of miniaturization, bulky tubes, pumps and valves common to current microfluidic devices must be replaced with micromachined fluid channels with integrated fluid control systems. Pneumatically actuated fluid control devices have been utilized in miniaturizing fluid control, but control of the pneumatics themselves is often a macroscopic process that limits decreasing overall system size. To provide a means for miniaturizing the pneumatics, an electrostatically actuated gas valve was integrated into a printed circuit board (PCB) and constructed utilizing PCB as a substrate for pneumatic channels, the valve structure, and a distribution system. Although electrostatically-actuated, microscale pneumatic valves have been realized previously, the novel PCB integration of pneumatic channels and an electrostatic valve, as presented in this work, allows for rapid prototype construction and electrical circuit integration, which makes the whole system inexpensive and thus possibly disposable. The valve was specifically manufactured by using a copper foil strip as the valve stopper and PCB traces were used as electrodes to generate an electric field to actuate the foil valve stopper over a hole in the PCB substrate, creating a one way valve. The valve could be stacked in multiple layers to create a three-way valve. The valve was tested to have a maximum operational pressure of 17 kPa when operated at 488 V. The valve was found to hold a static pressure of 197 kPa before valve wall rupture. The maximum life cycle of the valve prototype was found to be approximately 50,000 cycles. A power consumption of 2.2 mW when operated at a frequency of 2 Hz was observed. |
