Abstract: In a MEMS device employing a beam supported by transverse arms, potential bowing of the transverse arms caused by fabrication processes, temperature or local self-heating from resistive losses is accommodated by flexible terminations of the transverse arms. Alternatively, this bowing is controlled so as to provide selective biasing to the beam or mechanical advantage in the sensing of beam motion.

Abstract: In a MEMS device employing a beam supported by transverse arms, potential bowing of the transverse arms caused by fabrication processes, temperature or local self-heating from resistive losses is accommodated by flexible terminations of the transverse arms. Alternatively, this bowing is controlled so as to provide selective biasing to the beam or mechanical advantage in the sensing of beam motion.

Abstract: In a MEMS device employing a beam supported by transverse arms, potential bowing of the transverse arms caused by fabrication processes, temperature or local self-heating from resistive losses is accommodated by flexible terminations of the transverse arms. Alternatively, this bowing is controlled so as to provide selective biasing to the beam or mechanical advantage in the sensing of beam motion.

Abstract: A hybrid focal plane array (FPA) structure including a Balanced Composite Structure (BCS) in which several layers of materials having differing thermal expansion coefficients stabilize the FPA during cryogenic cooling. An optical substrate with a layer of an optically sensitive material detects impinging radiation. The optically sensitive material is coupled to a multiplexer (MUX) substrate via interconnection bumps. The MUX is bonded to a layer of a material having a high TEC. A rigid core layer is sandwiched between the MUX and a balancing layer formed of a material having similar mechanical and geometrical characteristics to the MUX substrate. The three-layer BCS consisting of the MUX, the rigid core layer and the balancing layer is designed to have an effective TEC matching that of the optical substrate. The bumps and the optically sensitive material are thus protected from undesirable stresses generated during thermal excursions, thereby resulting in substantially improved FPA reliability.

Abstract: Disclosed is a nondestructive test method for inspecting an object, including the steps of generating a surface acoustic wave at a first location on the object, detecting a harmonic of the generated wave at a second location on the object, and relating the characteristics of the detected wave to the remaining useful life of the object. The amplitude of the detected harmonic may be compared to standard amplitude values to predict the percentage of fatigue life remaining in the object, or the amplitude may be used to estimate the size and density of cracks in the object. Additionally, the harmonic wave may be detected for a range of stress values, the amplitude differential between the maximum harmonic amplitude and the minimum amplitude under compression calculated, and the differential related to the remaining useful life of the object.

Abstract: Acoustic signals are received, selectively filtered, and digitally processed, e.g., by digitizing an amplitude, the peak of an echo, or the transit time, and the digital data are stored in a memory whose storage cells are associated with particular frequencies. Other acoustical signals are similarly processed but compared with the reference data to obtain a spectral representation of differences or ratios.