title: An electromagnetic microvalve for pneumatic control of microfluidic systems.
abstract: An electromagnetic microvalve for pneumatic control of microfluidic devices has been designed, fabricated, and tested. The microvalve is composed of two parts: a miniature electromagnetic actuator and a valve body. The electromagnetic actuator consists mainly of a thin polydimethylsiloxane (PDMS)-based elastomer, which acts as the valve diaphragm. The diaphragm, used as a solid hydraulic medium, converts the large contact area of a valve core into a small contact area of valve head while maintaining a large stroking force. This microvalve remains closed because of a compressed mechanical spring force generated by the actuator. On the other hand, when a voltage is applied, the valve core moves up, relaxing the thin PDMS membrane, opening the microvalve. The fast open response (~17 ms) of the valve was achieved with a leak rate as low as 0.026 sccm at 200 KPa (N2) pressure. We tested the pertinent dynamic parameters such as flow rate in on/off mode, flow rate of duty cycles, and actuated frequencies in pulse width modulation (PWM) mode. Our method provides a simple, cheap, and small microvalve that avoids the bulky and expensive external pressure control solenoid manifold. This allows it to be easily integrated into portable and disposable devices.
authors.affiliation: Harbin Institute of Technology, Harbin, China.
authors.forename: Xuling
authors.initials: X
authors.lastname: Liu
authors.affiliation: Harbin Institute of Technology, Harbin, China lisongjing@hit.edu.cn.
authors.forename: Songjing
authors.initials: S
authors.lastname: Li
mesh_terms: D055590:Electromagnetic Phenomena; D006874:Hydrostatic Pressure; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D044085:Microfluidics / Q000295:instrumentation*
keywords: PDMS thin diaphragm; electromagnetic-static behavior; fluidic behavior; microvalve; pneumatic control