Caltech Micromachining Laboratory
Integrated Surface-Micromachined Mass Flow Controller
Project Abstract
An integrated surface-micromachined mass flow controller (MFC) that
consists of an electrostatically actuated microvalve and a thermal
flow sensor is presented here. With a unique design and utilizing a
multilayer Parylene process, the active microvalve and the flow
sensor are integrated onto a single chip to perform closed-loop flow
control. Sensitivity of the flow sensor is 55 mV/(mL/min) for
airflow and 12.2 mV/(nL/min) for water. The valve is actuated with a
10 kHz AC signal and an applied pressure of 21 kPa can be sealed with
an actuation voltage of 200 Vpeak (±200 V). For flow control, both
Pulse Width Modulation (PWM) and actuation voltage adjustment are
demonstrated. PWM shows better performance in terms of controllability
and linearity.
References
J. Xie, J. Shih and Y.C. Tai, "Integrated Surface-Micromachined Mass Flow Controller," Proceedings, The Sixteenth
IEEE International Conference on Micro Electro Mechanical Systems (MEMS '03), Kyoto, Japan, Jan. 19-23, pp. 20-23, (2003).
Involved Personnel
Jun Xie, Jason Shih
and Yu-Chong Tai
Related Publications
J. Xie, X. Yang, X.Q. Wang and Y.C. Tai, “Surface Micromachined Leakage Proof Parylene Check Valve”,
The 14th IEEE International Conference on Micro Electro Mechanical Systems (MEMS’01),
Interlaken, Switzerland, 2001, pp.539-542.
T.-J. Yao, K. Walsh and Y.-C. Tai, “Dielectric Charging Effects on Parylene Electrostatic Actuators”, The 15th IEEE
International Conference on Micro Electro Mechanical Systems (MEMS’02), Las Vegas, USA, 2002, pp.614-617
S. Wu, Q. Lin, Y. Yuen and Y.-C. Tai , “MEMS flow sensors for nano-fluidic applications,” Sensors
and Actuators A: Physical, 89 (1-2) (2001) pp. 152-158