We discuss photolithographic fabrication techniques and experimental results for a prototype electromagnetically driven microvalve. The valve is constructed on a silicon substrate, using a magnetic suspension spring with a valve cap, a valve plate with a 30 μm diameter bore, and an external coil for driving the valve cap. The external electromagnetic drive approach was chosen for its ease of use and practicality in controlling the valve actuator. The valve cap, made of soft magnetic material (NiFe) and supported by the spring, moves vertically as a result of the magnetic field applied by the external coil. To precisely adjust both the valve cap and the valve plate bore and to minimize fluid leakage, a new self-alignment process was developed. The valve is controlled by a 0.1-100 Hz rectangular magnetic field applied by the external coil. The resulting minimum gas flow rate can be controlled to within the neighborhood of 3 × 10-5 torr·l/s.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Hardware and Architecture
- Electrical and Electronic Engineering