A resonant micromachined electrostatic charge sensor

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)1499-1505
Journal / PublicationIEEE Sensors Journal
Volume8
Issue number9
Publication statusPublished - Sept 2008
Externally publishedYes

Abstract

A micromachined electrometer, based on the concept of a variable capacitor, has been designed, modeled, fabricated, and tested. The device presented in this paper functions as a modulated variable capacitor, wherein a dc charge to be measured is up-modulated and converted to an ac voltage output, thus improving the signal-to-noise ratio. The device was fabricated in a commercial standard SOI micromachining process without the need for any additional processing steps. The electrometer was tested in both air and vacuum at room temperature. In air, it has a charge-to-voltage conversion gain of 2.06 nV/e, and a measured charge noise floor of 52.4 e/rtHz. To reduce the effects of input leakage current, an electrically isolated capacitor has been introduced between the variable capacitor and input to sensor electronics. Methods to improve the sensitivity and resolution are suggested while the long-term stability of these sensors is modeled and discussed. © 2006 IEEE.

Research Area(s)

  • Electrostatic charge sensor, Micromechanical resonator, Transcapacitance amplifier (TCA), Variable capacitor, Vibrating reed electrometer

Citation Format(s)

A resonant micromachined electrostatic charge sensor. / Zhu, Yong; Lee, Joshua E.-Y.; Seshia, Ashwin A.
In: IEEE Sensors Journal, Vol. 8, No. 9, 09.2008, p. 1499-1505.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review