Axial asymmetry for improved sensitivity in MEMS piezoresistors

The strain induced resistance change is compared for asymmetric, symmetric and diffused piezoresistive elements. Finite element analysis is used to simulate the performance of a T-shaped piezoresistive MEMS cantilever, including a lumped parameter model to show the effect of geometric asymmetry on t...

Full description

Saved in:
Bibliographic Details
Published in:Journal of micromechanics and microengineering 2016-09, Vol.26 (9), p.95014
Main Authors: Shuvra, Pranoy Deb, McNamara, Shamus, Lin, Ji-Tzuoh, Alphenaar, Bruce, Walsh, Kevin, Davidson, Jim
Format: Article
Language:English
Subjects:
asymmetry
cantilever
piezoresistance
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The strain induced resistance change is compared for asymmetric, symmetric and diffused piezoresistive elements. Finite element analysis is used to simulate the performance of a T-shaped piezoresistive MEMS cantilever, including a lumped parameter model to show the effect of geometric asymmetry on the piezoresistor sensitivity. Asymmetric piezoresistors are found to be much more sensitive to applied load than the typical symmetric design producing about two orders of magnitude higher resistance change. This is shown to be due to the difference in the stress distribution in the symmetric and asymmetric geometries resulting in less resistance change cancellation in the asymmetric design. Although still less sensitive than diffused piezoresistors, asymmetric piezoresistors are sensitive enough for many applications, and are much easier to fabricate and integrate into MEMS devices.
ISSN:0960-1317
1361-6439
DOI:10.1088/0960-1317/26/9/095014