Giant resistivity change induced by strain in a composite of conducting particles in an elastomer matrix

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

“…Many groups have reported the piezoresistivity of metal-polymer composites. Ausanio et al, 2006, have investigated the piezoresistivity of nickel-silicon type elastomer (Universal 5 or Essil 244) composites under uniaxial strain. They have reported that the composites can switch from insulating to conducting state accompanied by resistivity change of ~ 9 orders of magnitude.…”

Magneto-piezoresistivity in iron particle-filled silicone: An alternative outlook for reading magnetic field intensity and direction

“…The sample length can be easily reduced by a laboratory knife. All the process has been described in some detail in previous papers [9,20,21]. No methodology has been applied to induce a preferential orientation of the Fe microparticles; therefore they resulted homogeneously distributed and randomly oriented.…”

“…The peculiar morphology of magnetic particles used in this work is different from the one employed in previous investigations (pseudospherical morphology with moderate roughness). The reason of this choice is to improve composite material performances, delineated on the basis of previous studies [9,20,21], in order to achieve three specific characteristics: i) bigger size particles; ii) better silicone entrapping among particle cavities during the mechanical dispersion process to isolate each particle from nearest ones; iii) lower transversal contraction able to give particle contact as consequence of the irregular surface protrusions; iv) preferential in plane magnetization of a single particle due to shape anisotropy. The positive effects of these listed material characteristics were verified by means of the sample performance as will be shown and discussed in Section 3.…”

“…In particular, several investigations have highlighted the existence of a giant piezoresistive effect (the electron conductivity can change by 9 orders of magnitude) in composite materials constituted by a silicone matrix filled by conductive microparticles at a volume fraction around percolation threshold [8][9][10].…”

Elastomer Application in Microsystem and Microfluidics

“…These materials exhibit Z-direction only electrical conduction, in combination with the compliant nature of the materials, can be exploited advantageously for a variety of electronic applications, including fine-pitch, area-array, circuit interconnects, circuit-testing, heat sink interfacing, and sensor devices 47,48 . The schematic diagram of this design structure is shown in Figure 1.…”