Ferroelectric Ceramic/Polymer Bimorph Sensor for Strain Measurement in Laminates.
Abstract
Work has been done by many workers in the past to investigate the bending (or flexural) piezoelectricity of poled polymer or ceramic films in the form of monomorphs or bimorphs. A single uniformly poled film when subjected to a uniform bending stress or strain will exhibit little piezoelectric effect due to the fact the average stress/strain across a cross-section of the film will tend to zero, the compressional stress/strain towards the inside of the bend cancelling with the extensional stress/strain towards the outside of the bend. The bending piezoelectric activity can be greatly enlarged by bonding the piezoelectric film to an electromechanically neutral material, thus forming a monomorph, or by bonding two piezoelectric films together to form a bimorph. Other methods used by other workers have been to produce a polarization gradient within a single piezoelectric film by an application of temperature gradients during poling or poling by electron beam irradiation. This report describes the results of investigations into the bending piezoelectricity of monomorphs and bimorphs constructed from ferroelectric composite materials of PTCa/P(VDF-TrFE) and PTCa/Epoxy. The theory of a piezoelectric bimorph acting as a cantilever is outlined and the results of the measurement of the piezoelectric strain coefficient h31 are given.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1996
- Accession Number
- ADA308554
Entities
People
- Dilip K. Das-Gupta
- M. P. Wenger
Organizations
- Bangor University