Progress on development of Al₂O₃-SiO₂ Ceramic MEMS-based monopropellant micropropulsion systemm

An Al₂O₃-SiO₂ ceramic MEMS-based micropropulsion system was designed and fabricated using new fabrication route. The micropropulsion system consists of five major components: propellant reservoir, injector, electrodes, combustion chamber, and micronozzle; all integrated into a single volume of 20 mm × 20 mm × 5 mm. 85-15 wt% of HAN-water mixture was self-prepared and used as propellant along with electrolytic mechanism for ignition. Performance of the system was predicted numerically. The system was fabricated by microcasting the well-dispersed suspension of submicron Al₂O₃ powder and PSZ preceramic resin into a lithography-prepared PDMS soft mold and sintering at 1200°C to form the ceramic composite. Shrinkage of about 20% was noticed after sintering. TGA analysis reveals good thermal stability of the composite as weight loss at temperature of 1000°C is as small as 1.3wt%. SEM-EDX analysis verifies the formation of Al₂O₃-SiO₂ composite as only elements of Al, O, and Si exist with a negligible amount of residual carbon. Current fabrication route hold the promise to fabricate MEMS micropropulsion system using different ceramic composite materials to meet different design requirements.