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At least 73 records · Page 4

Micromachined Tunneling Displacement Transducers for Physical Sensors

We have designed and constructed a series of tunneling sensors which take advantage of the extreme position sensitivity of electron tunneling. In these sensors, a tunneling displacement transducer, based on scanning tunneling microscopy principles, is used to detect the signal-induced motion of a sensor element. Through the use of high-resonant frequency mechanical elements for the transducer, sensors may be constructed which offer wide bandwidth, and are robust and easily operated. Silicon micromachining may be used to fabricate the transducer elements, allowing integration of sensor and control electronics. Examples of tunneling accelerometers and infrared detectors will be discussed. In each case, the use of the tunneling transducer allows miniaturization of the sensor as well as enhancement of the sensor performance.

Kenny, T. W.↗

Fabricating and using a micromachined magnetostatic relay or switch

A micromachined magnetostatic relay or switch includes a springing beam on which a magnetic actuation plate is formed. The springing beam also includes an electrically conductive contact. In the presence of a magnetic field, the magnetic material causes the springing beam to bend, moving the electrically conductive contact either toward or away from another contact, and thus creating either an electrical short-circuit or an electrical open-circuit. The switch is fabricated from silicon substrates and is particularly useful in forming a MEMs commutation and control circuit for a miniaturized DC motor.

Tai, Yu-Chong↗

Micromachined peristaltic pumps

Micromachined pumps including a channel formed between a first membrane and a substrate or between first and second flexible membranes. A series of electrically conductive strips is applied to a surface of the substrate or one of the membranes. Application of a sequential voltage to the series of strips causes a region of closure to progress down the channel to achieve a pumping action.

Hartley, Frank T.↗

Micromachined double resonator

A micromachined resonator mountable to an external support structure has a proof mass coupled to a base structure by a first spring structure, the base structure having a plurality of electrodes, and a second spring structure coupling the base structure to the external support structure.

Gutierrez, Roman↗

Micromachined Slits for Imaging Spectrometers

Slits for imaging spectrometers can now be fabricated to a precision much greater than previously attainable. What makes this possible is a micromachining process that involves the use of microlithographic techniques.

Wilson, Daniel↗

Micromachined Artificial Haircell

A micromachined artificial sensor comprises a support coupled to and movable with respect to a substrate. A polymer, high-aspect ratio cilia-like structure is disposed on and extends out-of-plane from the support. A strain detector is disposed with respect to the support to detect movement of the support.

Liu, Chang↗

Compact Micromachined Bandpass Filters for Infrared Planetary Spectroscopy

The thermal instrument strawman payload of the Jupiter Europa Orbiter on the Europa Jupiter Science Mission will map out thermal anomalies, the structure, and atmospheric conditions of Europa and Jupiter within the 7-100 micron spectral range. One key requirement for the payload is that the mass cannot exceed 3.7 kg. Consequently, a new generation of light-weight miniaturized spectrometers needs to be developed. On the path toward developing these spectrometers is development of ancillary miniaturized spectroscopic components. In this paper, we present a strategy for making radiation hard and low mass FIR band pass metal mesh filters. Our strategy involves using MEMS-based fabrication techniques, which will permit the quasi-optical filter structures to be made with micron-scale precision. This will enable us to achieve tight control over both the pass band of the filter and the micromachined silicon support structure architecture, which will facilitate integration of the filters for a variety of applications.

Brown, Ari D.↗

Compact Micromachined Infrared Bandpass Filters for Planetary Spectroscopy

The future needs of space based observational planetary and astronomy missions include low mass and small volume radiometric instruments that can operate in high radiation and low temperature environments. Here we focus on a central spectroscopic component, the bandpass filter. We model the bandpass response of the filters to target the wavelength of the resonance peaks at 20, 40, and 60 micrometers and report good agreement between the modeled and measured response. We present a technique of using common micromachining processes for semiconductor fabrication to make compact, free standing resonant metal mesh filter arrays with silicon support frames. The process can accommodate multiple detector array architectures and the silicon frame provides lightweight mechanical support with low form factor. We also present a conceptual hybridization of the filters with a detector array.

Merrell, Willie C., II↗

Micromachined Parts Advance Medicine, Astrophysics, and More

In the mid-1990s, Marshall Space Flight Center awarded two SBIR contracts to Potomac Photonics, now based in Baltimore, for the development of computerized workstations capable of mass-producing tiny, intricate, diffractive optical elements. While the company has since discontinued the workstations, those contracts set the stage for Potomac Photonics to be a leader in the micromachining industry, where NASA remains one of its clients.

Source record↗

Tag and seal employing a micromachine artifact

A method and apparatus to authenticate a tamper resistant seal that includes a population of particles embedded in an adhesive, the population including at least one micromachine artifact of a predetermined physical shape.

47 OTHER INSTRUMENTATION↗

Micromachined ceramic-based chipless LC resonator for high-temperature wireless sensing applications in harsh environments

The primary objective of this work was the fabrication and testing of a wireless LC resonator based on micro-patterned electroceramic materials for the monitoring of high-temperature systems. The twodimensional planar LC resonator sensors were designed and simulated using ANSYS Maxwell software, and these sensors were then fabricated from electrically conductive La 2 NiO 4 /Al 2 O 3 particulate inks. Initially, the phases of La 2 NiO 4 /Al 2 O 3 composite were evaluated by XRD. The patterning and deposition of the ink were completed using a novel micro-casting process onto Al 2 O 3 ceramic substrates, and the final pattern was bonded onto the substrate at 1200 °C for 2 h. The features and the reliability were analyzed by SEM microscopy. The frequency shift with respect to temperature was measured, which is directly related to changes in the sensor’s dielectric permittivity and pattern dimensions. The sensors were characterized at 500 °C–1000 °C in an ambient atmosphere with an RF signal ranging from 10–80 MHz at 175 kHz·s –1 sweep rate. The sensors showed a sensitivity of ~350 kHz °C –1 from 500 °C–1000 °C. Here, a new robust and adaptive signal processing approach was introduced to increase the degree of freedom for analyzing wireless sensors.

42 ENGINEERING↗

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↗