Near-zero expansion of ceramics by 3D printing thermally induced torsional structures

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

“…However, recent studies on CuO-based active materials focus more on sensing performance, while studies on structuralized sensing materials concentrate on improving mechanical reliability but ignore thermal stability. , The chiral-rotating sensing structures in this work open up the study of dimensional stability for gas sensors working at high temperatures. The CTE of the sensing structure in this work reached 1.04 × 10 –6 /K at 325 °C, revealing a marked decrease compared to the LiAlSiO 4 /kaolin negative Poisson’s ratio structure (1.9 × 10 –6 /K at 180 °C) . Because of the sensitization of the Ag-doped CuO nanocluster, the structure also exhibited competitive sensing performance to that reported in previous works.…”

“…The CTE of the sensing structure in this work reached 1.04 × 10 −6 /K at 325 °C, revealing a marked decrease compared to the LiAlSiO 4 /kaolin negative Poisson's ratio structure (1.9 × 10 −6 /K at 180 °C). 11 Because of the sensitization of the Ag-doped CuO nanocluster, the structure also exhibited competitive sensing performance to that reported in previous works. Although the response values of the structures were not impressive due to the high contact resistance and lacking specialized test methods for structural gas-sensitive materials, they still had a fast response/recovery speed, a wide detection range, and long-term stability, showing excellent application potential.…”

“…The mechanism of the adjustable thermal expansion behavior was explained by the heat-induced torsion effect of the sensing structures (Figure k). , A porous structure with a low solid ratio had the advantage of low expansion compared with a dense one (Figure S4b,c), while the unusual deformation behavior of the chiral-rotating structures further decreased the expansion. Ag-CuO/SiCuOC-F hardly deformed at a high temperature and therefore bore great thermal stress and strain at the connections of the struts.…”

“…10 Thus, structuralized sensing materials with this macroscopical design could be employed to realize low thermal expansion at their working temperatures. 11,12 SiOC is a kind of amorphous semiconductive ceramic with high mechanical and chemical stability, promising for low-expanded structure construction. It can be formed by the vat photopolymerization (VP) method using photocurable precursor resin, precisely transforming the designed concepts into solid structures.…”

“…Fortunately, the low thermal expanded materials can be realized according to the design concept of thermal metamaterials, whose stress can be dispersed or offset by the torsion, bending, and tension of the internal struts, while maintaining the dimensional stability of the integral construction . Thus, structuralized sensing materials with this macroscopical design could be employed to realize low thermal expansion at their working temperatures. , SiOC is a kind of amorphous semiconductive ceramic with high mechanical and chemical stability, promising for low-expanded structure construction. It can be formed by the vat photopolymerization (VP) method using photocurable precursor resin, precisely transforming the designed concepts into solid structures. , More importantly, the gas sensing capacity of SiOC can be activated by metal doping, suggesting the chemiresistive sensing behavior of p-type semiconductors .…”