30 research outputs found
MEMS Technology for Biomedical Imaging Applications
Biomedical imaging is the key technique and process to create informative images of the human body or other organic structures for clinical purposes or medical science. Micro-electro-mechanical systems (MEMS) technology has demonstrated enormous potential in biomedical imaging applications due to its outstanding advantages of, for instance, miniaturization, high speed, higher resolution, and convenience of batch fabrication. There are many advancements and breakthroughs developing in the academic community, and there are a few challenges raised accordingly upon the designs, structures, fabrication, integration, and applications of MEMS for all kinds of biomedical imaging. This Special Issue aims to collate and showcase research papers, short commutations, perspectives, and insightful review articles from esteemed colleagues that demonstrate: (1) original works on the topic of MEMS components or devices based on various kinds of mechanisms for biomedical imaging; and (2) new developments and potentials of applying MEMS technology of any kind in biomedical imaging. The objective of this special session is to provide insightful information regarding the technological advancements for the researchers in the community
George C. Marshall Space Flight Center Research and Technology Report 2014
Many of NASA's missions would not be possible if it were not for the investments made in research advancements and technology development efforts. The technologies developed at Marshall Space Flight Center contribute to NASA's strategic array of missions through technology development and accomplishments. The scientists, researchers, and technologists of Marshall Space Flight Center who are working these enabling technology efforts are facilitating NASA's ability to fulfill the ambitious goals of innovation, exploration, and discovery
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
Feature Papers in Electronic Materials Section
This book entitled "Feature Papers in Electronic Materials Section" is a collection of selected papers recently published on the journal Materials, focusing on the latest advances in electronic materials and devices in different fields (e.g., power- and high-frequency electronics, optoelectronic devices, detectors, etc.). In the first part of the book, many articles are dedicated to wide band gap semiconductors (e.g., SiC, GaN, Ga2O3, diamond), focusing on the current relevant materials and devices technology issues. The second part of the book is a miscellaneous of other electronics materials for various applications, including two-dimensional materials for optoelectronic and high-frequency devices. Finally, some recent advances in materials and flexible sensors for bioelectronics and medical applications are presented at the end of the book
Advanced Characterization and On-Line Process Monitoring of Additively Manufactured Materials and Components
This reprint is concerned with the microstructural characterization and the defect analysis of metallic additively manufactured (AM) materials and parts. Special attention is paid to the determination of residual stress in such parts and to online monitoring techniques devised to predict the appearance of defects. Finally, several non-destructive testing techniques are employed to assess the quality of AM materials and parts
Energy: A continuing bibliography with indexes
This bibliography lists 1546 reports, articles, and other documents introduced into the NASA scientific and technical information system from April 1, 1981 through June 30, 1981