Electric field sensor using electrostatic force deflection of a micro-spring supported membrane

An electric field sensor is shown which uses a micromachined micro-spring supported membrane as the sensing element. The sensing mechanism involves electrostatic force to deflect the membrane, and an optical position sensor to measure membrane movement. Measurement resolution was 5 kV/m for a dc field and 140 V/m for a 49 Hz ac field. It is shown that a bias voltage applied to the membrane can be used to increase measurement sensitivity. With a 17 kV/m dc bias field, a 0.3 V/m ac field at 97 Hz was detectable.

[1]  Hao Luo,et al.  A copper CMOS-MEMS Z-axis gyroscope , 2002, Technical Digest. MEMS 2002 IEEE International Conference. Fifteenth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.02CH37266).

[2]  L. Shafai,et al.  Microstrip phase shifter using ground-plane reconfiguration , 2004, IEEE Transactions on Microwave Theory and Techniques.

[3]  Cyrus Shafai,et al.  Frequency‐agile microstrip patch antenna using a reconfigurable mems ground plane , 2004 .

[4]  Mark N. Horenstein,et al.  A micro-aperture electrostatic field mill based on MEMS technology , 2001 .

[5]  F. Noto,et al.  Design and development of new electrostatic voltmeter using strain gauge , 1989 .

[6]  K. L. Scott,et al.  Electrostatic charge and field sensors based on micromechanical resonators , 2003 .

[7]  D. Balaraman,et al.  Low-cost low actuation voltage copper RF MEMS switches , 2002, 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No.02CH37278).

[8]  P. E. Secker,et al.  INDUSTRIAL ELECTROSTATICS: FUNDAMENTALS AND MEASUREMENTS , 1994 .