Simple measurement technique for resonance frequency of micromachined cantilevers

Somashekara Bhat; Enakshi Bhattacharya

doi:10.1117/12.698280

19 January 2007 Simple measurement technique for resonance frequency of micromachined cantilevers

Proceedings Volume 6463, Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS VI; 64630N (2007) https://doi.org/10.1117/12.698280
Event: MOEMS-MEMS 2007 Micro and Nanofabrication, 2007, San Jose, California, United States

Abstract

This paper discusses a simple electrical measurement technique to determine resonance frequency of surface micromachined cantilever beams that is also suitable for packaged devices. Measurements are done on oxide anchored doped polysilicon beams. If the beam is driven by an AC signal riding on the DC bias, the beam starts vibrating. When the drive frequency matches the natural frequency of the beam, the oscillation amplitude is maximum. In this measurement, the DC bias is fixed at a value lower than the pull-in voltage. A small AC bias is then applied such that the sum of the DC and the maximum amplitude of the AC is less than the pull-in voltage. The frequency of the AC is then swept and at resonance, because of large displacement, the beam is pulled in and this is detected by a current flowing between the beam and the substrate. By iteratively adjusting the DC bias it is possible to make sure that pull-in occurs only due to resonance and the frequency setting at this point gives the natural frequency of the beam. Measured values for different beam lengths were compared with Doppler Vibrometry results and gave an excellent match.

Citation Download Citation

Somashekara Bhat and Enakshi Bhattacharya "Simple measurement technique for resonance frequency of micromachined cantilevers", Proc. SPIE 6463, Reliability, Packaging, Testing, and Characterization of MEMS/MOEMS VI, 64630N (19 January 2007); https://doi.org/10.1117/12.698280

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available