Giant piezoresistivity in polymer-derived amorphous SiAlCO ceramics

The piezoresistive behavior of polymer-derived amorphous SiAlCO ceramic is studied in a temperature range of 25–300 °C. It is shown that the material exhibits a giant gage factor of 7000–16,000, much higher than that for any reported high-temperature materials. The result also reveals that the material exhibits a positive temperature-dependent piezoresistive stress coefficient within the temperature range. The unusual piezoresistivity of the material was attributed to the structure of the SiAlCO, which consists of highly disordered graphene-like carbon nanoclusters dispersed within an amorphous matrix comprising of SiC x O 4− x tetrahedra. The huge piezoresistivity, together with the processibility and low-cost, make the material very promising for high-temperature sensor applications.