Effects of the content level and particle size of nickel powder on the piezoresistivity ofcement-based composites/sensors

Abstract

To explore the effects of the content level and particle size of spikyspherical nickel powder on electrical conductivity and piezoresistivity, threetypes of spiky spherical nickel powder with different particle sizes (3–7 µm, 2.6–3.3 µm and2.2–2.8 µm) were dispersed into the cement–matrix to fabricate the nickel powder filled cement-basedcomposites/sensors. Experimental results indicate that a high content level and a smallpractical size are beneficial for the improvement of electrically conductivity. Thepiezoresistive sensitivities of composites/sensors with 20, 24 and 22 vol% of nickelpowder increase orderly when nickel powder particle size is in the range of 3–7 µm. The piezoresistive sensitivities of composites/sensors with different particle sizes of nickelpowder decrease with an increase of nickel powder particle sizes at 24 vol% of nickel powdercontent level. The piezoresistive sensitivity is highly dependent on the conductive networkin the composites, which is dominated by the content level and the particle size of the spikyspherical nickel powder.