Solvent-Based Polymer Swelling Characterization for the Development of the Nano/Micro-Particle Polymer Composite MEMS Corrosion Sensor

2014 ◽  
Author(s):  
Feng Pan ◽  
Abdoul Kader Maiga ◽  
Po-Hao Adam Huang
Keyword(s):  
Reaction Products ◽  
Material Transport ◽  
Sensing Element ◽  
Micro Electro Mechanical Systems ◽  
Polymer Swelling ◽  
Corrosion Sensor ◽  
Mems Technology ◽  
New Type ◽  
Oxide Removal

The concept of using Micro-Electro-Mechanical Systems (MEMS) for in-situ corrosion sensing and for long-term applications has been proposed and is currently under development by our research lab. This is a new type of sensing using MEMS technology and, to the knowledge of our team, has not been explored previously. The MEMS corrosion sensor is based on the oxidation of metal nano/micro-particle embedded in elastomeric polymer to form a composite sensing element. The polymer controls the diffusion into and out of the sensor while the corrosion of the metal particles inhibits electrical conduction which is used as the detection signal. The work presented here is based on part of the methods developed for the removal of native and process-induced metal oxides. A major aspect is the study of the swelling dynamics of the polymer matrix (polydimethylsiloxane, PDMS) intended for enhancing material transport of etchants into and reaction products out of the composite during oxide removal. More specifically, the characterization of the swelling of copper particles-PDMS composite samples in liquid solvent baths is presented.

Swelling-Etching Characterization of PDMS-Copper Particle for the Development of the Nano/Micro-Particle Polymer Composite MEMS Corrosion Sensor

2015 ◽  
Author(s):  
Abdoul Kader Maiga ◽  
Adam Huang
Keyword(s):  
Copper Particle ◽  
Theoretical Explanation ◽  
Reaction Products ◽  
Material Transport ◽  
Sensing Element ◽  
Small Disk ◽  
Swelling Agent ◽  
Corrosion Sensor ◽  
Oxide Removal

The concept of using Micro-Electro-Mechanical Systems (MEMS) for in-situ corrosion sensing and for long-term applications has been proposed and is currently under development by our research lab. This is a new type of sensing using MEMS technology and, to the knowledge of our team, has not been explored previously. The MEMS corrosion sensor is based on the oxidation of metal nano/micro-particle embedded in elastomeric polymer to form a composite sensing element. The polymer controls the diffusion into and out of the sensor while the corrosion of the metal particles inhibits electrical conduction which is used as the detection signal. The work presented here is based on the experimental wet-chemistry method developed for the removal of native and process-induced metal oxides. A major aspect is the study of the swelling dynamics of the polymer matrix (polydimethylsiloxane, PDMS) and its influence on the material transport of etchants into and reaction products out of the composite during oxide removal. The understanding of this process is important to the ultimate development of the MEMS corrosion sensor, where the swelling must be controlled sufficiently to prevent stress-induced delamination of the sensing element from the substrate. For the first time, the simultaneous swelling (toluene) and oxide removal (acetic acid) characterization of the copper particles embedded in PDMS will be published. The experimental setup consists of small disk samples of the composite (6.35mm diameter × 1mm thick) dropped into a 50mL beaker filled with the swelling agent (the amount of which is part of the parametric study). This is then followed by the addition of the etching agent after reaching the swelling time constants characterized in prior work. The full process is captured through a HD webcam set inverted underneath the beaker. The swelling and contraction process is analyzed in real-time, while post processing of the recorded video is available to verify unexpected responses. Data gather so far indicate interesting swelling recovery phenomenon that is mostly consistent with the two part kinetics of swelling and etching. However, some data also seem to suggest a third mechanism that may be explained by material stiffness changes as etching and swelling proceed simultaneously. A full set of data currently being gathered will provide more clues and aid in the development of a consistent theoretical explanation. The final goal of this series of experiment is to provide mathematical models of the observed phenomenon so they can be used to aid the development of the fabrication processes of the MEMS corrosion sensor.

Novel MEMS Fabry-Perot Interferometric Pressure Sensors

2010 ◽  
Vol 638-642 ◽  
pp. 1009-1014 ◽  
Author(s):  
Ivan Padron ◽  
Anthony T. Fiory ◽  
Nuggehalli M. Ravindra
Keyword(s):  
Optical Fiber ◽  
Rigid Body ◽  
Pressure Sensors ◽  
Sensing Element ◽  
Micro Electro Mechanical Systems ◽  
Considerable Advantage ◽  
Fabry Perot ◽  
Mems Technology ◽  
Interferometric Sensor ◽  
Novel Design

A novel design for a Fabry-Perot Interferometric Sensor (FPIS) consisting of a Fabry-Perot cavity formed between two bonded surfaces is discussed. The Fabry-Perot cavity and the optical fiber to which it is coupled are used as the sensing element and interconnect, respectively. The Fabry-Perot cavity is fabricated using the Micro Electro Mechanical Systems (MEMS) technology. The introduction of a center rigid body diaphragm gives this sensor considerable advantage when compared with previous Fabry-Perot cavity based sensors.

MEMS flexible thermal flow sensor for measurement of boundary layer separation

2016 ◽  
Vol 30 (15) ◽  
pp. 1650177 ◽  
Author(s):  
Jui-Ming Yu ◽  
Tzong-Shyng Leu ◽  
Jiun-Jih Miau ◽  
Shih-Jiun Chen
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Separation ◽  
Flow Sensor ◽  
Thermal Flow ◽  
Sensing Element ◽  
Suction Surface ◽  
Flow Sensors ◽  
Micro Electro Mechanical Systems ◽  
Thermal Flow Sensor ◽  
Mems Technology

Micro-electro-mechanical systems (MEMS) thermal flow sensors featured with high spatial resolutions, fast frequency response and minimal interference with fluid flow have been applied widely in boundary-layer studies and aerodynamic flow sensing and control due to the inherent outstanding performances. In this study, MEMS thermal flow sensors were designed and fabricated on a flexible skin using the MEMS technology. The dimension of a single sensing element was 200 [Formula: see text]m × 260 [Formula: see text]m, which had a resistance of about 200 [Formula: see text] after annealing. By configuring thermal flow sensors in either a single thermal flow sensor and a thermal tuft sensor, separation points of a two-dimensional (2D) LS(1) 0417 airfoil at various angles of attack could be precisely detected. The experimental results show good agreement with the hot wire sensor and particle traced flow visualization in detecting the separation point on the suction surface of the airfoil.

scholarly journals Real-Time Monitoring of HT-PEMFC

Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Chi-Yuan Lee ◽  
Fang-Bor Weng ◽  
Chin-Yuan Yang ◽  
Chun-Wei Chiu ◽  
Shubham-Manoj Nawale
Keyword(s):  
High Temperature ◽  
Real Time ◽  
Flow Rate ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Micro Electro Mechanical Systems ◽  
Fuel Distribution ◽  
Mems Technology ◽  
Exchange Membrane

During the electrochemical reaction of a high temperature proton exchange membrane fuel cell (HT-PEMFC), (in this paper HT-PEMFC means operating in the range of 120 to 200 °C) the inhomogeneity of temperature, flow rate, and pressure in the interior is likely to cause the reduction of ion conductivity or thermal stability weight loss of proton exchange membrane materials, and it is additionally likely to cause uneven fuel distribution, thereby affecting the working performance and service life of the HT-PEMFC. This study used micro-electro-mechanical systems (MEMS) technology to develop a flexible three-in-one microsensor which is resistant to high temperature electrochemical environments; we selected appropriate materials and process parameters to protect the microsensor from failure or damage under long-term tests. The proposed method can monitor the local temperature, flow rate, and pressure distribution in HT-PEMFC in real time.

scholarly journals Current and New Approaches to Predict the Deflections of One-Way Flexural Members with a Focus on Composite Steel Deck Slabs Voided by Circular Tubes

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 421
Author(s):  
Chang-Hwan Lee ◽  
Iman Mansouri ◽  
Jaehoon Bae ◽  
Jaeho Ryu
Keyword(s):  
Structural Function ◽  
Flexural Members ◽  
Long Span ◽  
Deck Slabs ◽  
New Type ◽  
New Perspective ◽  
Flexural Tests ◽  
Prediction Approach ◽  
Steel Deck

A new type of composite voided slab, the TUBEDECK (TD), which utilizes the structural function of profiled steel decks, has recently been proposed. Previous studies have confirmed that the flexural strength of TD slabs can be calculated based on the full composite contribution of the steel deck, but for long-span flexural members, the deflection serviceability requirement is often dominant. Herein, we derived a novel deflection prediction approach using the results of flexural tests on slab specimens, focusing on TD slabs. First, deflection prediction based on modifications of the current code was proposed. Results revealed that TD slabs exhibited smaller long-term deflections and at least 10% longer maximum span lengths than solid slabs, indicating their greater efficiency. Second, a novel rational method was derived for predicting deflections without computing the effective moment of inertia. The ultimate deflections predicted by the proposed method correlated closely with the deflection under maximum bending moments. To calculate immediate deflections, variation functions for the concrete strain at the extreme compression fiber and neutral axis depth were assumed with predictions in good agreement with experiments. The proposed procedure has important implications in highlighting a new perspective on the deflection prediction of reinforced concrete and composite flexural members.

scholarly journals Dynamic Modeling and Anti-Disturbing Control of an Electromagnetic MEMS Torsional Micromirror Considering External Vibrations in Vehicular LiDAR

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 69
Author(s):  
Yong Hua ◽  
Shuangyuan Wang ◽  
Bingchu Li ◽  
Guozhen Bai ◽  
Pengju Zhang
Keyword(s):  
Dynamic Model ◽  
Optical Switching ◽  
Control Method ◽  
Sliding Mode ◽  
Algorithm Design ◽  
Coupling Model ◽  
Micro Electro Mechanical Systems ◽  
Mems Technology ◽  
Torsional Micromirror ◽  
Dynamic Coupling Model

Micromirrors based on micro-electro-mechanical systems (MEMS) technology are widely employed in different areas, such as optical switching and medical scan imaging. As the key component of MEMS LiDAR, electromagnetic MEMS torsional micromirrors have the advantages of small size, a simple structure, and low energy consumption. However, MEMS micromirrors face severe disturbances due to vehicular vibrations in realistic use situations. The paper deals with the precise motion control of MEMS micromirrors, considering external vibration. A dynamic model of MEMS micromirrors, considering the coupling between vibration and torsion, is proposed. The coefficients in the dynamic model were identified using the experimental method. A feedforward sliding mode control method (FSMC) is proposed in this paper. By establishing the dynamic coupling model of electromagnetic MEMS torsional micromirrors, the proposed FSMC is evaluated considering external vibrations, and compared with conventional proportion-integral-derivative (PID) controls in terms of robustness and accuracy. The simulation experiment results indicate that the FSMC controller has certain advantages over a PID controller. This paper revealed the coupling dynamic of MEMS micromirrors, which could be used for a dynamic analysis and a control algorithm design for MEMS micromirrors.

scholarly journals Study of the Synchrotron Photoionization Oxidation of Alpha-Angelica Lactone (AAL) Initiated by O(3P) at 298, 550, and 700 K

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4070
Author(s):  
Golbon Rezaei ◽  
Giovanni Meloni
Keyword(s):  
Atomic Oxygen ◽  
Fossil Fuels ◽  
Reaction Products ◽  
Photoionization Mass Spectrometry ◽  
Natural Substances ◽  
Primary Products ◽  
Major Reaction ◽  
Angelica Lactone ◽  
Significant Attention

In recent years, biofuels have been receiving significant attention because of their potential for decreasing carbon emissions and providing a long-term renewable solution to unsustainable fossil fuels. Currently, lactones are some of the alternatives being produced. Many lactones occur in a range of natural substances and have many advantages over bioethanol. In this study, the oxidation of alpha-angelica lactone initiated by ground-state atomic oxygen, O(3P), was studied at 298, 550, and 700 K using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at the Lawrence Berkeley National Lab (LBNL). Photoionization spectra and kinetic time traces were measured to identify the primary products. Ketene, acetaldehyde, methyl vinyl ketone, methylglyoxal, dimethyl glyoxal, and 5-methyl-2,4-furandione were characterized as major reaction products, with ketene being the most abundant at all three temperatures. Possible reaction pathways for the formation of the observed primary products were computed using the CBS–QB3 composite method.

A Fiber Optic Probe for Gas Total Temperature Measurement in Turbomachinery

1995 ◽  
Vol 117 (4) ◽  
pp. 635-641 ◽  
Author(s):  
S. R. Kidd ◽  
J. S. Barton ◽  
P. Meredith ◽  
J. D. C. Jones ◽  
M. A. Cherrett ◽  
...  
Keyword(s):  
Fiber Optics ◽  
High Speed ◽  
Gas Temperature ◽  
Fiber Optic Probe ◽  
Sensing Element ◽  
Unsteady Temperature ◽  
High Bandwidth ◽  
New Type ◽  
Total Temperature ◽  
Optic Probe

This paper describes the design, operation, construction, and demonstration of a new type of high-bandwidth unsteady temperature sensor based on fiber optics, and capable of operating in a high-speed multistage research compressor with flow representative of jet engine conditions. The sensing element is an optical coating of zinc selenide deposited on the end of an optical fiber. During evaluation in aerodynamic testing, a 1 K gas temperature resolution was demonstrated at 9.6 kHz and an upper bandwidth limit of 36 kHz achieved.

A Low-Range Drift-Free Bio-compatible Pressure Sensor Based on P(VDF-TrFE) Piezoelectric Thin Film

2009 ◽  
Vol 1222 ◽  
Author(s):  
Xiaoyang Li ◽  
Timothy Reissman ◽  
Fan Yu ◽  
Edwin C. Kan
Keyword(s):  
Thin Film ◽  
Blood Pressure ◽  
Pressure Sensor ◽  
Equivalent Circuit Model ◽  
Swelling Pressure ◽  
Pressure Monitoring ◽  
Sensing Element ◽  
Piezoelectric Resonance ◽  
Piezoelectric Thin Film

AbstractA low-range pressure sensor (0-100kPa) based on the P(VDF-TrFE) piezoelectric thin film is proposed, where the long-term drift is eliminated by operating near the piezoelectric resonance. The pressure sensor is designed for blood pressure and tissue swelling pressure monitoring. The poled 50μm±1μm P(VDF-TrFE) copolymer film is used as the sensing element, with all fabrication and assembly materials biocompatible. A modified Butterworth-Van Dyke (BVD) [1] equivalent circuit model is used to characterize the sensor behavior. The pressure sensor exhibits negligible drift in weeks of operation. The device shows a sensitivity of 0.038MHz/kPa resonance frequency shift under stress, which leads to a maximum readout change of 1.1%/kPa in the present setup.

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