The Piezoresistive Effect In Microflexures

The objective of this research is to present a new model for predicting the piezoresistive effect in microflexures experiencing bending stresses. A linear model describing piezoresistivity exists for members in pure tension and compression. Extensions of this model to more complex loading conditions do not match experimental results. An accurate model of piezoresistivity in complex loading conditions would expand the design possibilities of piezoresistive devices. A new model to predict piezoresistive effects in tension, compression, and more complex loading conditions is proposed. The focus of this research is to verify a unidirectional form of this proposed model for microflexures in tension and bending. Implementation of the unidirectional form of the model involves geometric design, stress analysis, and electrical analysis. One of the ways to implement the model is with finite-element analysis (FEA). The piezoresistive FEA for flexures (PFF) algorithm is an FEA implementation of the unidirectional form of the model for flexures. A case study is then given in which the resistance curves of two test devices are predicted with the PFF algorithm. Results from the PFF implementation of the unidirectional form of the model show a close comparison between analytical prediction and experimental results. This new model could contribute to optimized sensors, feedback control of microdevices, nanopositioning, and self-sensing microdevices.

Name thesis:degree_name

MS

Grantor dc:publisher

Brigham Young University - Provo

Author dc:creator

• Johns, Gary K.

• piezoresistivity
• compliant mechanisms
• MEMS
• sensors
• Mechanical Engineering

Language dc:language

English

Repository record dc:identifier

https://scholarsarchive.byu.edu/etd/1074

OAI identifier oai:identifier

oai:scholarsarchive.byu.edu:etd-2073