Accession Number : ADA308561

Title :   Design and Construction of Smart Materials Based on Piezoresistive Sensors and Multilayer Actuators.

Descriptive Note : Final rept. 1 Sep 92-29 Feb 96,

Corporate Author : ALFRED UNIV NY

Personal Author(s) : Schulze, Walter A. ; Carlson, William B.

PDF Url : ADA308561

Report Date : 26 APR 1996

Pagination or Media Count : 6

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.

Descriptors :   *DETECTORS, *PIEZOELECTRICITY, *ELECTRICAL RESISTANCE, *TEMPERATURE COEFFICIENTS, STRESSES, MECHANICAL PROPERTIES, TRANSITION METALS, OPTIMIZATION, HIGH RATE, EXPOSURE(GENERAL), LAYERS, MATERIALS, INSULATION, BENDING, CERAMIC MATERIALS, PURITY, PRECIPITATION, CONFIGURATIONS, ACTUATORS, SEMICONDUCTING FILMS, BARIUM TITANATES, SINTERING.

Subject Categories : Electrical and Electronic Equipment
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE