Piezoresistive effect in epoxy–graphite composites

Abstract

In this work, we investigate the piezoresistive response of epoxy-graphite composites. A resistive thick-film Wheatstone bridge is deposited by screen-printing onto an alumina beam, a weight is then applied on the tip of the beam and the resulting electrical signal response is recorded, allowing the calculation of the gauge factor. The characterization was made at room temperature, 60°C and 100°C for different matrixes (epoxies with different glass transition temperatures, Tg) and particles sizes (4 µm and 15 µm). The creep of the signal in time and temperature was also observed. The present work shows also the tremendous effect of Tg on piezoresistive behavior: the high Tg epoxy demonstrating better stability in time and temperature than the other one.

Usage of Conductive Polymer Composite as the Object Film of Eddy Current Gap Sensor

“…The silicone rubber film between the adjacent carbon nanotubes, where the tunneling effect occurs, is called as 'tunneling film' [24]. The conclusions on the tunneling effect have been verified and supported by many previous researches [13]- [15], [24]- [26]. Furthermore, the contacts among carbon nanotubes also contribute to the conductivity of the composite.…”

Impedance characteristics of surface pressure-sensitive carbon black/silicone rubber composites

“…Pressure-sensitive materials based on piezoresistive-sensing mechanisms are widely used owing to their attractive advantages, including feasible preparation, low cost, and easy signal collection [12]. Therefore, they are potential to be used to develop flexible pressure-sensitive sensors [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

A flexible pressure-sensitive array based on soft substrate

“…This kind of materials is potential for developing flexible pressure-sensitive array [13][14][15][16][17][18][19][20][21][22] .…”

“…It has been widely reported that some conductive polymer films or elastomeric rubbers filled with conductive carbon black particles showed piezoresistive behaviors [13][14][15][16][17][18][19][20][21][22] . They kept high elasticity and conductive when loads applied.…”