Development of Latching Type Large Vertical-Travel Microactuator

2005 ◽  
Author(s):  
Risaku Toda ◽  
Eui-Hyeok Yang
Keyword(s):  
Plane Motion ◽  
Proof Of Concept ◽  
Test Device ◽  
Comb Drive ◽  
Pzt Actuator ◽  
Comb Drives ◽  
Out Of Plane ◽  
Sequential Activation ◽  
Vertical Travel

This paper describes design, fabrication and preliminary characterization of a proof-of-concept vertical-travel microactuator, providing linear motion and high precision positioning in space. The microactuator is capable of providing latching function when it is un-powered to maintain its position. The microactuator consists of two opposing comb drive actuator dies, a slider and bulk PZT actuators sandwiched between the dies. The slider is inserted between clutches. Comb drives are connected to the clutches to engage/disengage clutching. Sequential activation of the comb drives (in-plane motion) and the PZT actuator (out-of-plane motion) provides cumulative linear travel of the slider. The novelty of the slider insertion approach include (1) post-fabrication engagement of comb teeth enabling thick wafer DRIE process for comb drive actuators and (2) stressed tethers enabling zero-power latching. A test device was fabricated and assembled. By applying 100V∼300V DC to the electrostatic comb drive, lateral actuation of clutches was observed. Vertical actuation by PZT was also confirmed using WYKO RST plus interferometer.

Out-of-Plane Comb-Drive Lever Actuator

2000 ◽  
Author(s):  
Hung-Yi Lin ◽  
Weileun Fang
Keyword(s):  
Electrostatic Force ◽  
Plane Motion ◽  
Comb Drive ◽  
Out Of Plane ◽  
Gap Closing

Abstract In the present study, an out-of-plane motion actuator driven by the electrostatic force is designed and fabricated. The electrostatic force generated by the gap closing electrodes and the comb electrodes will be studied. Moreover, a lever motion transmitting mechanism is proposed to modulate the motion of the actuators. Although the space between the driving electrodes is limited, the lever motion transmitting mechanism could enlarge the traveling distance. The applications of the out-of-plane motion actuator are remarkably increased due to the assistant of the transmitting mechanism.

Fabrication and Characterization of Vertical Travel Linear Microactuator

2004 ◽  
Author(s):  
Risaku Toda ◽  
Eui-Hyeok Yang
Keyword(s):  
Piezoelectric Actuator ◽  
Actuation Voltage ◽  
Silicon On Insulator ◽  
Test Bed ◽  
Device Structure ◽  
Beam Geometry ◽  
Out Of Plane ◽  
Fabrication And Characterization ◽  
Vertical Travel

This paper describes design, fabrication and characterization of a proof-of-concept vertical travel linear microactuator designed to provide out-of-plane actuation for high precision positioning applications in space. The microactuator is designed to achieve vertical actuation travel by incorporating compliant beam structures within a SOI (Silicon on Insulator) wafer. Device structure except for the piezoelectric actuator is fabricated on the SOI wafer using Deep Reactive Ion Etch (DRIE) process. Incremental travel distance of the piezoelectric actuator is adjustable at nanometer level by controlling voltage. Bistable beam geometry is employed to minimize initial gaps between electrodes. The footprint of an actuator is approximately 2 mm × 4 mm. Actuation is characterized with LabVIEW-based test bed. Actuation voltage sequence is generated by the LabVIEW controlled power relays. Vertical actuation in the range of 500 nm over 10-cycle was observed using WYKO RST Plus Optical Profiler.

Non-Contact Mechanical Testing and Characterization of Micro-Scale Structures

2006 ◽  
Author(s):  
Jian Chen ◽  
Ganesh Subramanian ◽  
Justin Ricci ◽  
Liang Ban ◽  
Cetin Cetinkaya
Keyword(s):  
Plane Motion ◽  
Cantilever Beams ◽  
Micro Scale ◽  
New Class ◽  
Sensor Platform ◽  
Out Of Plane ◽  
Modes Of Vibration ◽  
Scale Structures ◽  
Micro Cantilever

A non-contact testing and characterization method based on air-coupled acoustic excitation and interferometric displacement measurements of micro-scale MEMS structures at room conditions is introduced. In demonstrating its potential uses in testing and characterization, the present non-contact approach is applied to (i) micro-cantilever beams and (ii) rotational disk oscillators. Air-coupled multi-mode excitation of micromechanical cantilever-type oscillators under a pulsed acoustic field generated by an air-coupled transducer is demonstrated and reported. Also, the testing and characterization of a micro-scale rotational disk oscillator developed for a new class of sensor platform is demonstrated. The main design objective of the rotational disk oscillator class is to overcome the out-of-plane motion related sensitivity limitations of the cantilever-based sensors at high frequency operations. The dynamics of the rotational disk oscillators is more complex than micro-cantilever beams due to its in-plane motion in addition to its various out-of-plane modes of vibration. The fabrication of a rotational disk oscillator requires a suspended disk whose underside is visibly inaccessible due to a narrow micro-gap. In addition to the dynamic characterization of the cantilever beams and rotational disk oscillators, the current investigation demonstrates that the presented approach can address unique structural concerns such as the verification of a gap separation of the rotational oscillator from the underlying silicon substrate. Utilizing the proposed technique, the resonant frequencies of the oscillator structures are obtained and its potential uses in the testing and characterization of micro-scale structures are discussed. The major specific advantages of the introduced approach include that (i) its noncontact nature can eliminate testing problems associated with stiction and adhesion, and (ii) it allows direct mechanical characterization and testing of components and sub-components of a micro-scale devices.

scholarly journals Bulk PZT Actuator for Parallel out-of-plane motion: The Superiority of Torsion Deformation over Bending Deformation

2016 ◽  
Vol 168 ◽  
pp. 1513-1516
Author(s):  
Nadav Maccabi ◽  
Inbar (Hotzen) Grinberg ◽  
Adne Kassie ◽  
Shai Shmulevich ◽  
David Elata
Keyword(s):  
Plane Motion ◽  
Pzt Actuator ◽  
Bending Deformation ◽  
Out Of Plane ◽  
Torsion Deformation

Characterization of the Dynamical Response of a Micromachined G-Sensor to Mechanical Shock Loading

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Daniel Jordy ◽  
Mohammad I. Younis
Keyword(s):  
Element Model ◽  
Plane Motion ◽  
Squeeze Film ◽  
Dynamical Response ◽  
Mechanical Shock ◽  
Mems Devices ◽  
Squeeze Film Damping ◽  
Out Of Plane ◽  
Gap Width

Squeeze film damping has a significant effect on the dynamic response of microelectromechanical system (MEMS) devices that employ perforated microstructures with large planar areas and small gap widths separating them from the substrate. Perforations can alter the effect of squeeze film damping by allowing the gas underneath the device to easily escape, thereby lowering damping. By decreasing the size of the holes, damping increases and the squeeze film damping effect increases. This can be used to minimize the out-of-plane motion of the microstructures toward the substrate, thereby minimizing the possibility of contact and stiction. This paper aims to explore the use of the squeeze film damping phenomenon as a way to mitigate shock and minimize the possibility of stiction and failure in this class of MEMS devices. As a case study, the performance of a G-sensor (threshold accelerometer) employed in an arming and fusing chip is investigated. The effect of changing the size of the perforation holes and the gap width separating the microstructure from the substrate are studied. A multiphysics finite-element model built using the software ANSYS is utilized for the fluidic and transient structural analysis. A squeeze film damping model, for both the air underneath the structure and the flow of the air through the perforations, is developed. Results are shown for various models of squeeze film damping assuming no holes, large holes, and assuming a finite pressure drop across the holes, which is the most accurate way of modeling. It is found that the threshold of shock that causes the G-sensor to contact the substrate has increased significantly when decreasing the holes size or the gap width, which is very promising to help mitigate stiction in this class of devices, thereby improving their reliability.

scholarly journals Characterization of design grammar of peptides for regulating liquid droplets and aggregates of FUS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kiyoto Kamagata ◽  
Rika Chiba ◽  
Ichiro Kawahata ◽  
Nanako Iwaki ◽  
Saori Kanbayashi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Electrostatic Interactions ◽  
Amyloid Fibrils ◽  
Droplet Formation ◽  
Liquid Droplets ◽  
Proof Of Concept ◽  
Aggregate Formation ◽  
Fused In Sarcoma ◽  
Dynamics Simulations

AbstractLiquid droplets of aggregation-prone proteins, which become hydrogels or form amyloid fibrils, are a potential target for drug discovery. In this study, we proposed an experiment-guided protocol for characterizing the design grammar of peptides that can regulate droplet formation and aggregation. The protocol essentially involves investigation of 19 amino acid additives and polymerization of the identified amino acids. As a proof of concept, we applied this protocol to fused in sarcoma (FUS). First, we evaluated 19 amino acid additives for an FUS solution and identified Arg and Tyr as suppressors of droplet formation. Molecular dynamics simulations suggested that the Arg additive interacts with specific residues of FUS, thereby inhibiting the cation–π and electrostatic interactions between the FUS molecules. Second, we observed that Arg polymers promote FUS droplet formation, unlike Arg monomers, by bridging the FUS molecules. Third, we found that the Arg additive suppressed solid aggregate formation of FUS, while Arg polymer enhanced it. Finally, we observed that amyloid-forming peptides induced the conversion of FUS droplets to solid aggregates of FUS. The developed protocol could be used for the primary design of peptides controlling liquid droplets and aggregates of proteins.

Electrical Characterization of InAs/(GaIn)Sb Infrared Superlattice Photodiodes for the 8 to 12νm Range

1999 ◽  
Vol 607 ◽  
Author(s):  
L. Bürkle ◽  
F. Fuchs ◽  
R. Kiefer ◽  
W. Pletschen ◽  
R. E. Sah ◽  
...  
Keyword(s):  
Electrical Characterization ◽  
Cutoff Wavelength ◽  
Saturation Current ◽  
Diffusion Limited ◽  
Saturation Current Density ◽  
Out Of Plane ◽  
Reverse Saturation Current ◽  
The Magnetic Field ◽  
Diode Current

AbstractInAs/(GaIn)Sb superlattice photodiodes with a cutoff wavelength of 8.711μm show adynamic impedance of R0A= 1.5 kωcm2at 77 K and a responsivity of 2 A/W, corresponding to a detectivity of D*= 1 x 1012 cmv√Hz/W. Diffusion limited performance is observed above 100 K. At lower temperatures the diodesare limited by generation-recombination currents. An analysis of the influence of different diode sidewall passivations on the surface contribution to the diode leakage current is presented. The out-of-plane electron mobility as well as the relative contributions of the electron and hole diffusion currents to the diode current were determined by a measurement of the magnetic field dependence of the reverse saturation current density of the diodes

Out-of-Plane Motion Effects in Microscopic Particle Image Velocimetry

2003 ◽  
Vol 125 (5) ◽  
pp. 895-901 ◽  
Author(s):  
Michael G. Olsen ◽  
Chris J. Bourdon
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Laser Sheet ◽  
Plane Motion ◽  
Entire Volume ◽  
Measurement Volume ◽  
Microscopic Particle ◽  
Image Velocimetry ◽  
Out Of Plane ◽  
Signal Peak

In microscopic particle image velocimetry (microPIV) experiments, the entire volume of a flowfield is illuminated, resulting in all of the particles in the field of view contributing to the image. Unlike in light-sheet PIV, where the depth of the measurement volume is simply the thickness of the laser sheet, in microPIV, the measurement volume depth is a function of the image forming optics of the microscope. In a flowfield with out-of-plane motion, the measurement volume (called the depth of correlation) is also a function of the magnitude of the out-of-plane motion within the measurement volume. Equations are presented describing the depth of correlation and its dependence on out-of-plane motion. The consequences of this dependence and suggestions for limiting its significance are also presented. Another result of the out-of-plane motion is that the height of the PIV signal peak in the correlation plane will decrease. Because the height of the noise peaks will not be affected by the out-of-plane motion, this could lead to erroneous velocity measurements. An equation is introduced that describes the effect of the out-of-plane motion on the signal peak height, and its implications are discussed. Finally, the derived analytical equations are compared to results calculated using synthetic PIV images, and the agreement between the two is seen to be excellent.

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