STUDY ON PREPARATION AND PIEZORESISTIVE CHARACTERISTICS OF TVS-MODIFIED POLYMER-DERIVED SIBCN CERAMICS

Due to the excellent piezoresistive properties and high-temperature stability, polymer-derived ceramics (PDCs) have been recognized as promising for sensing. However, enhancing their sensitivity remains challenging yet critical. In this work, a precursor modification strategy is presented and the enhancement in piezoresistive sensing performance of its derived ceramics is quantitatively characterized. The pre-designed hydrosilylation between original precursor and vinyl-contained tetravinylsilane (TVS) allowed the precise regulation of free carbon content and conductive network formation. The polymer-greenbody-ceramic conversion process was monitored, where the resultant ceramic was lightweight (~1.9   g/cm³) and superior thermal stable. It is revealed that pyrolysis temperature and TVS content synergistically govern the graphitization evolution and piezoresistive behavior. The optimized ceramic exhibited a gauge factor of 4181, representing a 46.7% enhancement over the original samples, accompanied by cyclic analyses that confirmed its durability. This study establishes a feasible approach to designing high-sensitivity SiBCN sensors and advances their application through composition-structure-property tailoring.