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Results for “tunneling tip accelerometer, accelerometer fabrication”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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3 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Design and Process Considerations for a Tunneling Tip Accelerometer

In this paper, we discuss issues related to the fabrication of a bulk micromachined single axis accelerometer. The accelerometer is designed to have a full scale range of ten millig and a sensitivity of tens of nanog. During the process, three distinctly different die are fabricated. These are subsequently assembled using an ally bonding technique. During the bonding operation, electrical contacts are made between layers. The accelerometer is controlled by electrostatic force plates above and below the proof mass. The lower electrode has a dual role. In operation, it provides a necessary control electrode. When not in operation, it is used to clamp the proof mass and prevents its motion. Results of the fabrication process and initial testing of the clamping function are reported.

tunneling tip accelerometer, accelerometer fabrica↗
NASA NTRS1995

Progress Toward a Bulk Micromachined Tunneling Tip Microaccelerometer

Ultrasensitive accelerometers are needed for microgravity measurement of orbital drag and active isolation systems. We have designed an accelerometer capable of measuring accelerations of the order of 10(i) g. A tunneling tip sensor can be used as a position sensor with a potential performance advantage of two orders of magnitude over capacitive sensors. In this paper, we disclose our progress in the fabrication and measurement of a bulk microaccelerometer which employs a tunneling tip. Fully assembled accelerometers consisting of four separate die have been fabricated. The device employs a unique folded spring system with a low spring constant. To protect the tunneling tip, we have employed electrostatic clamping. Stiction has not been observed, but the required clamping voltage is greater than expected. We have developed a simple model to analyze our results.

micromachining, microaccelerometer↗
NASA NTRS1995

Tunneling Tip Protection for a Bulk Micromachined Accelerometer

Ultrasensitive accelerometers (on the order of 10-8 g) are needed by NASA for the measurement of orbital drag, and for seismic measurements on other planets. Silicon micromachined devices are attractive because they are light weight and smaller than conventional accelerometers. A method is presented here for fabricating a bulk micromachined accelerometer which incorporates a tunneling tip.

Accelerometer↗