Vaporizing liquid microthruster

• Published in: Sensors and actuators. A. Physical. 2000-05, Vol.83 (1), p.231-236
• Main Authors: Mukerjee, E.V, Wallace, A.P, Yan, K.Y, Howard, D.W, Smith, R.L, Collins, S.D
• Format: Article
• Language: English
• Subjects: Applied sciences; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Fluid; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Integrated circuits; Mechanical instruments, equipment and techniques; Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology; Micromachining; Micromechanical devices and systems; Microthruster; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Spacecraft; Wafer bonding
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/S0924-4247(99)00389-1

MEMS technology is expanding into increasingly diverse applications. As part of a micropropulsion system, microthruster attitude controls have been micromachined in silicon. This paper presents the microthruster design, fabrication, and test results. Fluid injected into a microchamber is vaporized by resistive silicon heaters. The exiting vapor generates the thruster force as it exits a silicon micro-nozzle. The vaporization chamber, inlet and exit nozzles were fabricated using anisotropic wet etching of silicon. With a 5 W heater input, injected water could be vaporized for input flow rates up to a maximum of 0.09 cc/s. Experimental testing produced thruster force magnitudes ranging from 0.15 mN to a maximum force output of 0.46 mN depending on fabrication parameters: chamber length, nozzle geometries, heater power, and liquid flow rates.