Design and Construction of Smart Materials Based on Piezoresistive Sensors and Multilayer Actuators.
Abstract
PTCR (positive temperature coefficient of resistance) barium titanate was the active material for a ceramic sensor which employed piezoresistivity to detect changes in applied stress. High purity, chemically prepared barium titanate was donor-doped at an optimum level of 0.30 at% lanthanum to provide semiconductivity. A transition metal counterdopant was added at a level of less than 0.10 at% in some cases, to enhance the PTCR effect. The donor dopant and counterdopant were added to the powder through a special precipitation technique. Tape-cast sheets of undoped and PTCR BaTiO3 were laminated to produce a three-layer 'trilaminate' - a sintered structure which has two semiconducting PTCR layers separated by an insulating layer. The trilaminate was exposed to mechanical stress in a four-point bend configuration (placing one semiconducting layer completely in tension, the other in compression), and the resistivities for both stress states were measured concurrently as functions of applied stress and temperature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 26, 1996
- Accession Number
- ADA308561
Entities
People
- Walter A. Schulze
- William B. Carlson
Organizations
- Alfred University