NASA Tech Briefs, June 1990

Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Space and Earth Sciences, Computer Systems, and Scientific Data Analysis Support, Volume 1

This Final Progress Report covers the specific technical activities of Hughes STX Corporation for the last contract triannual period of 1 June through 30 Sep. 1993, in support of assigned task activities at Goddard Space Flight Center (GSFC). It also provides a brief summary of work throughout the contract period of performance on each active task. Technical activity is presented in Volume 1, while financial and level-of-effort data is presented in Volume 2. Technical support was provided to all Division and Laboratories of Goddard's Space Sciences and Earth Sciences Directorates. Types of support include: scientific programming, systems programming, computer management, mission planning, scientific investigation, data analysis, data processing, data base creation and maintenance, instrumentation development, and management services. Mission and instruments supported include: ROSAT, Astro-D, BBXRT, XTE, AXAF, GRO, COBE, WIND, UIT, SMM, STIS, HEIDI, DE, URAP, CRRES, Voyagers, ISEE, San Marco, LAGEOS, TOPEX/Poseidon, Pioneer-Venus, Galileo, Cassini, Nimbus-7/TOMS, Meteor-3/TOMS, FIFE, BOREAS, TRMM, AVHRR, and Landsat. Accomplishments include: development of computing programs for mission science and data analysis, supercomputer applications support, computer network support, computational upgrades for data archival and analysis centers, end-to-end management for mission data flow, scientific modeling and results in the fields of space and Earth physics, planning and design of GSFC VO DAAC and VO IMS, fabrication, assembly, and testing of mission instrumentation, and design of mission operations center

BULK-PIEZOELECTRIC TRANSDUCTION OF MICROSYSTEMS WITH APPLICATIONS TO BATCH-ASSEMBLY OF MICROMIRRORS, CAPACITIVE SENSING, AND SOLAR ENERGY CONCENTRATION

Electromechanical modeling, actuation, sensing and fabrication aspects of bulkpiezoelectric ceramic integration for microsystems are investigated in this thesis. A small-signal model that describes the energy exchange between surface micromachined beams and bulk-lead zirconium titanate (PZT) actuators attached to the silicon substrate is presented. The model includes detection of acoustic waves launched from electrostatically actuated structures on the surface of the die, as well as their actuation by bulk waves generated by piezoelectric ceramics. The interaction is modeled via an empirical equivalent circuit, which is substantiated by experiments designed to extract the model parameters. As a die level application of bulk-PZT, an Ultrasound Enhanced Electrostatic Batch Assembly (U2EBA) method for realization of 3-D microsystems is demonstrated. U2EBA involves placing the die in an external DC electric field perpendicular to the substrate and actuating the die with an off-chip, bulk-piezoelectric ceramic. Yield rates reaching up to 100% are reported from 8×8 arrays of hinged mirrors with dimensions of 180 × 100 micrometre-squared. U2EBA is later improved to provide temporary latching at intermediate angles between fully horizontal and vertical states, by using novel latching structures. It is shown that the micromirrors can be trapped and freed from different rotation angles such that zero static power is needed to maintain an angular position. The zero-idle-power positioning of large arrays of small mirrors is later investigated for energy redirection and focusing. All-angle LAtchable Reflector (ALAR) concept is introduced, and its application to Concentrated Solar Power (CSP) systems is discussed. The main premise of ALAR technology is to replace bulky and large arrays of mirrors conventionally used in CSP technologies with zeroidle- power, semi-permanently latched, low-profile, high-fill factor, micrometer to centimeter scale mirror arrays. A wirelessly controlled prototype that can move a 2-D array of mirrors, each having a side length of less than 5 cm, in two degrees of freedom to track the brightest spot in the ambient is demonstrated. Capacitive sensing using bulk-piezoelectric crystals is investigated, and a Time- Multiplexed Crystal based Capacitive Sensing (TM-XCS) method is proposed to provide nonlinearity compensation and self-temperature sensing for oscillator based capacitive sensors. The analytical derivation of the algorithm and experimental evidence regarding the validity of some of the relations used in the derivation are presented. This thesis also presents results on microfluidic particle transport as another application of bulk-PZT in microsystems. Experiments and work regarding actuation of micro-scale, fluorescent beads on silicon nitride membranes are described