Piezoresistivity of Hi‐Nicalon Type‐S Silicon Carbide‐Based Fiber

Abstract

Piezoresistivity effect of a silicon carbide-based ceramic fiber (Nicalon family) was evaluated when a single fiber was buried at the tensile plane in a plastic rectangular bar subjected to bending to apply a stable tensile strain. Electrical resistivity change during the bending was monitored by a digital highresistance meter. From the fracture strain, Young's modulus, and the resistivity change, the piezoresistance coefficient is calculated to be 1.6 ؋ 10 ؊11 m 2 /N, which is in agreement with the reported value for silicon carbide single crystals and our own reported value for polycrystalline silicon carbide ceramics.

Progress of One-Dimensional SiC Nanomaterials: Design, Fabrication and Sensing Applications

“…Fracture strain approaching 10% was achieved for a diamond-structure SiC nanowire with a <111> direction. The calculated piezoresistance coefficient of this SiC nanowire was −1.15 × 10 −11 Pa −1 , which is similar to the coefficient of the bulk material [ 117 , 118 , 119 ]. Pulliam et al [ 120 ] developed a micromachined SiC fiber optic pressure sensor for use in the extreme temperatures and pressures of propulsive environments.…”

Improvement of piezoresistance properties of silicon carbide ceramics through co-doping of aluminum nitride and nitrogen

“…On silicon carbide polycrystal which is advantageous for fabrication cost and mechanical strength, we have already reported a piezoresistivity coefficient comparable to that for single crystal [2][3][4][5][6][7]. Based on these data, we proposed a direct strain or pressure sensing at elevated temperature using silicon carbide ceramics of which sensitivity is barely feasible [4][5][6]. For sensing near room temperature, however, silicon single crystal is suitable due to its favorable sensitivity and fabrication cost.…”

“…We have already examined the effect of dopant on the practically advantageous silicon carbide ceramics to improve the piezoresistive effect. The piezoresistivity coefficient is suggested to increase with increasing the doping amount within the solid solution limit in both group III and group V elements doping , e.g., 1.5 mol% in the case of aluminum [5,6,8]. We have also examined the codoping of Al metal and atomospheric nitrogen.…”