Open AccessDifferential piezoresistive sensing in a bulk‐mode micromechanical resonator
Author(s) -
Wei Xueyong,
Seshia Ashwin A.
Publication year - 2013
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2012.0789
Subject(s) - piezoresistive effect , resonator , materials science , mode (computer interface) , optoelectronics , differential (mechanical device) , nanotechnology , engineering , computer science , aerospace engineering , operating system
A report is presented on a differential piezoresistive sensing approach for transducing the motional response of bulk‐mode micromechanical resonators. High‐frequency bulk‐mode micoresonators have inherently high stiffness and demonstrate limited range of motion, which in turn presents challenges for the capacitive sensing method in the presence of large parasitic feedthrough. A differential piezoresistive sensing approach is implemented in this Letter to substantially reject the effects of parasitic capacitive feedthrough, leaving the response recovered directly from the measurement. With differential pick‐up, a 33 dB drop of feedthrough has been achieved and a resonant peak magnitude of 14 dB is obtained for a drain current of 1 mA, which is shown to be approximately 20 times higher than that obtained for the conventional piezoresistive sensing scheme. This method also enables a low DC voltage for capacitively driving the bulk‐mode resonator. As an example, a resonant peak magnitude of 5 dB is demonstrated using 3.55 mA drain current and 5 V DC driving voltage.