Zero-Expanded Gas Sensing of Chiral-Rotating Chemiresistive SiCuOC Structures

Chiral-rotating gas sensing structures composed of chemiresistive-sensitized SiCuOC have been presented to provide a facile method for reducing the thermal expansion of gas sensors working at high temperatures. The structures can disperse thermal stress by heat-induced torsion of their units while maintaining the dimensional stability of the integral construction. Vat photopolymerization constructed Cu-doped SiOC substrates with a high resolution, while Ag-doped CuO nanoclusters further modified them. Taking advantage of the synergistic sensitization effect of the substrate and the surface sensing layer, the structure exhibited a high response/recovery speed (24/32 s) and a response value of 54.45% to 100 ppm acetone; 97.19% of its initial response was maintained after a long-term detection. The thermal expansion coefficient of the sensing structure reached 1.04 × 10^-6/K at the working temperature, revealing a near-zero expansion. Compressive strength and Young's modulus of the structures were 31.93 MPa and 3.38 GPa, respectively. Meanwhile, the structures realized regular gas detection under pressure (85.02 kPa) and thermal (325 °C) loading, as their high deformation resistance protected the integrity and connection of the surface sensing layer. Thus, the work proved the dimensional stabilization effect of chemiresistive sensing structures with chiral-rotating design, realizing stable gas detection in complex loading environments.