Piezoresistivity and Mechanical Behavior of Metal-polymer Composites under Uniaxial Pressure

Abstract

The piezoresistive response of copper and nickel particles reinforced polydimethylsiloxane (PDMS) polymer, forming metal-polymer composites were investigated under uniaxial pressure. Electrical and mechanical properties of composite samples containing Cu and Ni conductive fillers at different loadings in polydimethylsiloxane (PDMS) polymer matrix have been presented here. Well-dispersed metal-polymer composites were fabricated by a wet mixing route. The resulting Cu-PDMS and Ni-PDMS composite samples show the resistivity changes by more than 2 and 10 orders of magnitude around 4MPa pressure, respectively. The mechanical tests have shown that these composite samples have high stress sensitivity which makes them good piezoresistive candidates for practical applications.

Smart piezoresistive tunnelling composite for flexible robotic sensing skin

“…The gauge factor values calculated for the 250 phr, the 200 phr and the 150 phr samples are 48, 42 and 27, respectively. These gauge factors are higher than the values found for polymer composites prepared with zinc particles or other copper particles (∼30 or lower) [22,23], but lower than those found for nickel based composites (∼200) [23,31], where the metal content is higher. Obviously the correlation between piezosensitivity and GF is the elastic modulus of the functional material, hence a composite with a low gauge factor could have a high piezosensitivity, which is more interesting for fabricating a tactile sensor array.…”

“…The role of the tips in the functional material is well-rendered by comparing the piezoresistive response of the microstructured copper-PDMS with other tunnelling composites with rounded fillers. Actually a considerably lower variation of the electrical resistance at the same applied pressure was obtained in composites using zinc, nickel and also smoother copper particles [22,23].…”

Capacitive pressure-sensitive composites using nickel–silicone rubber: experiments and modeling

“…The conductive polymers typically comprise conductive micron-or nano-scale particles dispersed into a flexible insulating polymer matrix. Currently, most studies are focused on their piezo-resistive effect, which also inspired conductive polymers for development of flexible tactile sensors [19][20][21][22]. A study by Guo et al [23] presented a piezo-capacitive sensor printed on a flexible textile substrate, with a carbon black-silicone rubber (SR) composite as the dielectric layer.…”

Alignment of carbon iron into polydimethylsiloxane to create conductive composite with low percolation threshold and high piezoresistivity: experiment and simulation

“…The percolation threshold is extremely sensitive to the conducting particle volume fraction and structures. In previous studies, conductive composites filled with CI [6][7][8], Zn [9], Cu [10,11], Ni [12][13][14] and Fe3O4@Ag [15,16] particles were produced and tested. The isotropic composites have very high percolation threshold (>20 vol% in general).…”