Piezoresistivity of Nickel Powder Filled Epoxy Resin Composites
Han Baozhong1, Zhou Daocheng2, Han Baoguo2
1. Key Laboratory of Engineering Dielectric and Its Application, Ministry of Education Harbin University of Science and Technology Harbin 150040 China 2. Harbin Institute of Technology Harbin 150090 China
Abstract：The measurement method of electrical resistivity of nickel powder filled epoxy resin composites was explored. The variation regularity of electrical resistivity of nickel powder filled epoxy resin composites with different contents of nickel powder and flexible epoxy resin under uniaxial compression was studied. The generation mechanism of piezoresistivity of nickel powder filled epoxy resin composites was discussed according to static electrical resistivity and variation in volume of composites under compression. The research results show that the electrical resistance of composites measured with the direct current two-electrode method is consistent with that measured with the direct current four-electrode method, which indicates that the direct current two-electrode method is feasible for measurement of electrical resistivity of this kind of composites. The fabricated nickel powder filled epoxy resin composites have good piezoresistivity. The absolute value of the fractional change in electrical resistivity reaches 69.98% maximum under compressive stress in a range from 0MPa to 12.5MPa. The sensitivity of piezoresistivity of nickel powder filled epoxy resin composites increases when the content of nickel powder decreases and the content of flexible epoxy resin increases. The generation of piezoresistivity of this kind of composites is due to the enhancement of tunnel effect, which is caused by the decrease in volume of composites under compression.
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2011, Vol. 26 
