Development of a rapid-response flow-control system using MEMS microvalve arrays

A method for providing high-resolution gas flow control using microelectromechanical systems (MEMS) has been developed and tested. The micromachined component consists of an array of 61 synchronized microvalves operating in parallel. A number of tests were conducted on microvalves of various designs to characterize their operation. The best performing of these was used with a prototype flow controller. Additionally, a mathematical model of the flow system and controller was derived to predict the response of the system to various changes in operating conditions. This work describes the design, modeling, and testing of a compact, stand-alone mass flow controller (MFC) to demonstrate high resolution, fast response flow control using MEMS microvalves. The device consists of a microvalve array packaged with a micro flow sensor and a microprocessor-based control system. The high bandwidth of microvalves allows an atypical flow control architecture. The controller regulates a pulsewidth-modulated (PWM) signal sent to the valve array and is capable of both open- and closed-loop control. A mathematical model was also developed to predict the dynamic performance of the system under various operating conditions. Additional advantages of the MEMS flow-control system include low-power consumption, low fabrication costs, and scalable precision.