Stephen Vargo

AN OVERVIEW OF MEMS-BASED MICROPROPULSION DEVELOPMENTS AT JPL

Development of MEMS (Microelectromechanical Systems) micropropulsion at the Jet Propulsion Laboratory (JPL) is reviewed. This includes a vaporizing liquid micro-thruster for microspacecraft attitude control, a micro-ion emgine for microspacecraft primary propulsion or large spacecraft fine attitude control, as well as several valve studies, including a solenoid valve studied in collaboration with Moog Space Products Division, and a piezoelectric micro-valve.

Characterization of Kovar-Pyrex anodically bonded samples: a new packaging approach for MEMS devices

The ability to anodically bond Kovar to Pyrex 7740 significantly expands the packaging approaches available for MEMS devices. This technique greatly simplifies and reliably interconnects micropropulsion MEMS components (thrusters, valves) with the attached propellant system. Experimental bonds of Kovar plates and fixtures have been made to numerous Pyrex samples in order to investigate the strength and failure modes of these bonds. An emphasis on experimentally bonding at low temperatures (~200

MEMS technology at NASA's Jet Propulsion Laboratory

DEGC) using large voltages (< 2000V) was also a important parameter of this research and a current microvalve project at JPL. Bond strength measurements have been made using calibrated pull and burst tests with their results being comparable to typical silicon to Pyrex anodic bonds. Detailed bonding conditions for the tested samples have been included in this manuscript to aid the MEMS designer in using this approach to satisfy their packaging needs.

Heat transfer measurements and calculations for a MEMS fabricated resistojet - Initial results

The MEMS Technology Group is part of the Microdevices Laboratory (MDL) at the Jet Propulsion Laboratory (JPL). The group pursues the development of a wide range of advanced MEMS technologies that are primarily applicable to NASAs robotic as well as manned exploration missions. Thus these technologies are ideally suited for the demanding requirements of space missions namely, low mass, low power consumption and high reliability, without significant loss of capability. End-to-end development of these technologies is conducted at the MDL, a 38,000 sq. ft. facility with approximately 5500 sq. ft. each of cleanroom (class 10 - 100,000) and characterization laboratory space. MDL facilities include computer design and simulation tools, optical and electron-beam lithography, thin film deposition equipment, dry and wet etching facilities including Deep Reactive Ion Etching, device assembly and testing facilities. Following the fabrication of the device prototypes, reliability testing of these devices is conducted at the state-of-the-art Failure Analysis Laboratory at JPL.