A Silicon Thermomechanical In-Plane Microactuation System for Large Displacements in Aqueous Environments

2011 ◽  
Author(s):  
Gregory L. Holst ◽  
Brian D. Jensen
Keyword(s):  
Microelectromechanical Systems ◽  
Aqueous Environment ◽  
Large Displacements ◽  
Experimental Demonstration ◽  
Experimental Procedure ◽  
Microelectromechanical System ◽  
Actuation System ◽  
Test Parameters ◽  
Depth Analysis ◽  
Aqueous Environments

This paper presents an underwater, silicon, thermal microactuation system capable of moving a 200 μN load to a displacement of 110 μm. Its function relies on a thermal actuator capable of 9 μm of displacement in an aqueous environment. This actuator is combined with a ratcheting device to achieve the 110 μm of displacement. The system is a microelectromechanical system (MEMS) fabricated with a two layer surface-micromachining process, PolyMUMPS. The actuation system is designed to provide motion to biological microelectromechanical systems (BioMEMS) in aqueous environments. This paper presents the design and experimental demonstration of the actuation system. The in-depth analysis of the thermal, mechanical, and fabrication aspects of the actuation system are outlined, and the experimental procedure and test parameters are discussed.

scholarly journals Coulomb-actuated microbeams revisited: experimental and numerical modal decomposition of the saddle-node bifurcation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Anton Melnikov ◽  
Hermann A. G. Schenk ◽  
Jorge M. Monsalve ◽  
Franziska Wall ◽  
Michael Stolz ◽  
...  
Keyword(s):  
Finite Element ◽  
Microelectromechanical Systems ◽  
Dynamic Range ◽  
Dynamic Performance ◽  
Major Step ◽  
Element Analysis ◽  
Electrostatic Actuators ◽  
Voltage Range ◽  
Drive Voltage ◽  
Depth Analysis

AbstractElectrostatic micromechanical actuators have numerous applications in science and technology. In many applications, they are operated in a narrow frequency range close to resonance and at a drive voltage of low variation. Recently, new applications, such as microelectromechanical systems (MEMS) microspeakers (µSpeakers), have emerged that require operation over a wide frequency and dynamic range. Simulating the dynamic performance under such circumstances is still highly cumbersome. State-of-the-art finite element analysis struggles with pull-in instability and does not deliver the necessary information about unstable equilibrium states accordingly. Convincing lumped-parameter models amenable to direct physical interpretation are missing. This inhibits the indispensable in-depth analysis of the dynamic stability of such systems. In this paper, we take a major step towards mending the situation. By combining the finite element method (FEM) with an arc-length solver, we obtain the full bifurcation diagram for electrostatic actuators based on prismatic Euler-Bernoulli beams. A subsequent modal analysis then shows that within very narrow error margins, it is exclusively the lowest Euler-Bernoulli eigenmode that dominates the beam physics over the entire relevant drive voltage range. An experiment directly recording the deflection profile of a MEMS microbeam is performed and confirms the numerical findings with astonishing precision. This enables modeling the system using a single spatial degree of freedom.

Abrasion Under Humide Condition for Tool Steels H-13 and AISI D-2

Tribology ◽  
2006 ◽  
Author(s):  
I. Hilerio ◽  
M. Vite ◽  
M. A. Barro´n ◽  
H. Jime´nez ◽  
G. D. Alva´rez
Keyword(s):  
Wear Resistance ◽  
Mining Industry ◽  
Wear Test ◽  
Aqueous Environment ◽  
Aqueous Environments ◽  
Ionic Process ◽  
New Material ◽  
Aqueous Conditions ◽  
Wear Tool

In the present work, is developed the tribologic characterization of steels AISI H-13 and D-2, submitted to nitruration ionic process to determine wear resistance in aqueous conditions. Wear test are realized with an abrasion wear tool in an aqueous environment, designed and constructed by SEPI, ESIME, IPN, according to the norm ASTM G105-89. The aim of this investigation is to use a new material at lower prize which has an excellent wear resistance properties for high abrasion in aqueous environments, as occurs in several cases as mining industry equipments.

scholarly journals Bis(benzylamine) monomers: One-pot preparation and application in dendrimer scaffolds for removing pyrene from aqueous environments

2013 ◽  
Vol 9 ◽  
pp. 2320-2327 ◽  
Author(s):  
Olivia N Monaco ◽  
Sarah C Tomas ◽  
Meghan K Kirrane ◽  
Amy M Balija
Keyword(s):  
First Generation ◽  
Second Generation ◽  
Formation Constants ◽  
Aqueous Environment ◽  
One Pot ◽  
Inclusion Formation ◽  
Aqueous Environments ◽  
Protective Groups ◽  
Benzaldehyde Derivatives ◽  
Weight Structures

Bisimine and bisamine AB2 monomers have been synthesized from 3,5-diaminobenzoic acid and benzaldehyde derivatives without the need for protective groups or purification. This monomer preparation is universal for various electron-donating and electron-withdrawing benzaldehyde substrates. To demonstrate the versatility of these previously unreported AB2 monomers in the formation of high molecular weight structures, novel first-generation dendrimers and hybrid second-generation dendrimers have been synthesized. Using fluorescence spectroscopy, pyrene was shown to be removed from an aqueous environment upon exposure to thin dendrimer films, with the first-generation dendrimer removing 70% of the pyrene within 30 min and the hybrid second-generation dendrimers removing 38–52%. Inclusion formation constants were calculated to be on the order of 109–1011 M−1 and are comparable to the values of previously reported macromolecules. These results illustrate that size may not influence pyrene removal as effectively as composition.

scholarly journals Oxidative Transformation of Controlled Substances by Manganese Dioxide

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Webber Wei-Po Lai ◽  
Angela Yu-Chen Lin ◽  
Sheng-Yao Yang ◽  
Ching-Hua Huang
Keyword(s):  
Fulvic Acid ◽  
Lower Solution ◽  
Aqueous Environment ◽  
Solution Ph ◽  
Oxidative Transformation ◽  
Controlled Substances ◽  
Toc Removal ◽  
Rate Limiting Step ◽  
Aqueous Environments ◽  
Rate Limiting

This study investigated the oxidative transformation of four controlled substances (ketamine, methamphetamine, morphine, and codeine) by synthesized MnO2(δ-MnO2) in aqueous environments. The results indicated that ketamine and methamphetamine were negligibly oxidized by MnO2and, thus, may be persistent in the aqueous environment. However, morphine and codeine were able to be oxidized by MnO2, which indicated that they are likely naturally attenuated in aqueous environments. Overall, lower solution pH values, lower initial compound concentrations, and higher MnO2loading resulted in a faster reaction rate. The oxidation of morphine was inhibited in the presence of metal ions (Mn2+, Fe3+, Ca2+, and Mg2+) and fulvic acid. However, the addition of Fe3+and fulvic acid enhanced codeine oxidation. A second-order kinetics model described the oxidation of morphine and codeine by MnO2; it suggested that the formation of a surface precursor complex between the target compound and the MnO2surface was the rate-limiting step. Although the target compounds were degraded, the slow TOC removal indicated that several byproducts were formed and persist against further MnO2oxidation.

Experimental demonstration of phase correction with a 32×32 microelectromechanical systems mirror and a spatially filtered wavefront sensor

2006 ◽  
Vol 31 (3) ◽  
pp. 293 ◽  
Author(s):  
Lisa A. Poyneer ◽  
Brian Bauman ◽  
Bruce A. Macintosh ◽  
Daren Dillon ◽  
Scott Severson
Keyword(s):  
Microelectromechanical Systems ◽  
Phase Correction ◽  
Wavefront Sensor ◽  
Experimental Demonstration

On the Micromechanical Characterization of Metallic MEMS by a Hybrid Microtester

2015 ◽  
Author(s):  
Jennifer Wardlow ◽  
Seyed Allameh
Keyword(s):  
Mechanical Properties ◽  
Microelectromechanical Systems ◽  
Local Deformation ◽  
Small Scale ◽  
Large Displacements ◽  
Mems Devices ◽  
Surface Flaws ◽  
Micromechanical Characterization ◽  
Position Monitoring

Mechanical testing of microelectromechanical systems (MEMS) components helps investigate the reliability of MEMS devices used especially in vital applications such as life-supporting, medical, aerospace or automotive technologies. This paper discusses the development and use of a hybrid micromechanical system that combines the advantages of a macroscale slow-action screw-driven stage producing large displacements with a small-scale fast-action piezo-driven actuator. The main advantage is to study mechanical properties of small structures such as thick and thin films developing cracks that travel on millimeter scale during fatigue. The combination of piezo position monitoring with image-recognition-based local deformation determination allows specification of the beginning of phenomena such as micro-void-induced softening with relative accuracy. Such studies are most useful for investigation of the onset of nucleation of microcracks from fatigue-induced surface flaws. The significance of finding the onset of crack propagation lies in the fact that crack initiation constitutes the major portion of fatigue life for small structures (occasionally up to 99.3%).

Layer-by-layer printing of cells and its application to tissue engineering

2004 ◽  
Vol 845 ◽  
Author(s):  
Priya Kesari ◽  
Tao Xu ◽  
Thomas Boland
Keyword(s):  
Tissue Engineering ◽  
Microelectromechanical Systems ◽  
Cell Types ◽  
Three Dimensions ◽  
Layer By Layer ◽  
Hematopoietic Stem ◽  
On Demand ◽  
Cell Structures ◽  
Aqueous Environments ◽  
Multiple Cell

ABSTRACTTissues and organs exhibit distinct shapes and functions nurtured by vascular connectivity. In order to mimic and examine these intricate structure-function relationships, it is necessary to develop efficient strategies for assembling tissue-like constructs. Many of the top-down fabrication techniques used to build microelectromechanical systems, including photolithography, are attractive due to the similar feature sizes, but are not suitable for delicate biological systems or aqueous environments. A layer-by layer approach has been proposed by us to pattern functional cell structures in three dimensions. Freeform cell structures are created by the inkjet method, in which cells are entrapped within hydrogels and crosslinked on demand. The cells are viable, functional and show potential for cell maturation as exemplified by the diversion of hematopoietic stem cells into multiple cell types. These results show promise for many tissue engineering applications.

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