Experimental study on use of nickel powder-filled Portland cement-based composite for fabrication of piezoresistive sensors with high sensitivity

Nickel powder-filled Portland cement-based composite was prepared by adding nickel powder as functional filler into conventional Portland cement-based materials, and piezoresistive sensors were fabricated by embedding four loop electrodes in the nickel powder-filled Portland cement-based composite. The relationship between the fractional change in electrical resistivity and the stress/strain of piezoresistive sensors was established for the compressive stress and was found to be in the range from 0 to 12.5 MPa. Experimental results indicate that the electrical resistivity of nickel powder-filled Portland cement-based composite under uniaxial compression decreases by 62.6144% within elastic regime, which justifies the use of this composite in the fabrication of piezoresistive sensors with high sensitivity to stress and sensitivity to strain (gauge factor). The sensitivity of piezoresistive sensors to compressive stress is higher than 0.050092 MPa−1 and goes up to 0.123648 MPa−1. The gauge factor of piezoresistive sensors is higher than 895.450 and goes up to 1929.500. It is therefore concluded that the newly developed piezoresistive sensors have a high sensitivity to stress/strain, and they can be used for measurement of stress/strain or force/deformation.