SiC Nanowire Sponges as Electro-Pressure Sensors

Light-weight, flexible and highly porous ceramic are very attractive to engineering applications due to their good inertness, stable and excellent mechanical properties. We here report such SiC nanowire (SiCNW) sponges and demonstrate their multi-functionalities. They were simply generated by reacting SiO2 with the sustainable kitchen sugar, using NH4Cl as a blowing agent. The as-grown highly porous SiCNW sponges exhibit a core-shell structure, with an extremely low density in the range of 115-125 mg/cm3 (against 3.21 g/cm3 for the bulk). The core part is comprised of short and tangled SiC whiskers with SiC flakes embedded, whilst the shell layer consists of numerous smooth SiCNWs of hundred micrometres long. These sponges exhibit a compressive modulus of ~1.35 MPa and recoverability under cyclic compression loading for 100 cycles at a strain of 20%. Meanwhile, the SiCNW sponges exhibit interesting electromechanical sensing capability with a gauge factor up to 87 and stable wide-range compression-resistan...