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Novel Test Fixture For Characterizing Mems Switch Microcontact Reliability And Performance, Protap Kumar Mahanta
Novel Test Fixture For Characterizing Mems Switch Microcontact Reliability And Performance, Protap Kumar Mahanta
Dissertations (1934 -)
Microelectromechanical systems (MEMS) switch is considered as a better alternative than the conventional solid-state DC and RF switches due to their low contact resistance approximately 1 Ω, near-zero power consumption approximately 0 W, low insertion loss approximately 0.2 dB, and high isolation approximately -30 dB. However, reliability is a great concern for them to be ubiquitously used by the industry for specific applications. Switching dynamics and microcontact surface physics play the critical role in determining their reliability. A simple, quick, and efficient test fixture is required to study the contact surface physics as well as to optimize the switching dynamics.In …
Low-Cost, Water Pressure Sensing And Leakage Detection Using Micromachined Membranes, Farhana Anwar
Low-Cost, Water Pressure Sensing And Leakage Detection Using Micromachined Membranes, Farhana Anwar
Master's Theses (2009 -)
This work presents the only known SOI membrane approach, using Microelectromechanical systems (MEMS) fabrication techniques, to address viable water leakage sensing requirements at low cost. In this research, membrane thickness and diameter are used in concert to target specific stiffness values that will result in targeted operational pressure ranges of approximately 0-120 psi. A MEMS membrane device constructed using silicon-on-insulator (SOI) wafers, has been tested and packaged for the water environment. MEMS membrane arrays will be used to determine operational pressure range by bursting.Two applications of these SOI membranes in aqueous environment are investigated in this research. The first …
Liquid Flowmeter Using Thermal Measurement; Design And Application, Woojae Chung
Liquid Flowmeter Using Thermal Measurement; Design And Application, Woojae Chung
Master's Theses (2009 -)
This thesis presents flowmeter devices which can measure flowrate, pressure and temperature offlowing liquid samples using thermal measurement method. Typical thermal mass flowmeter usesthermal properties of materials to obtain flow features only for gases. We designed and fabricatedflowmeter devices with various functionalities such as: measuring properties of flowing liquid andidentifying the type of liquid samples.Thermal measurement methods using temperature sensor is a key of our flowmeter’s workingprinciple. The thermal mass flowmeter consists of a glass capillary, a tungsten wire heater, and aresistance temperature detector (RTD) sensor. The heater and sensors are integrated on …
Thermal Management Using Mems Bimorph Cantilever Beams, Ronald A. Coutu Jr., R. S. Lafleur, J. P.K. Walton, Lavern A. Starman
Thermal Management Using Mems Bimorph Cantilever Beams, Ronald A. Coutu Jr., R. S. Lafleur, J. P.K. Walton, Lavern A. Starman
Electrical and Computer Engineering Faculty Research and Publications
This paper examines a passive cooling technique using microelectromechanical systems (MEMS) for localized thermal management of electronic devices. The prototype was designed using analytic equations, simulated using finite element methods (FEM), and fabricated using the commercial PolyMUMPs™ process. The system consisted of an electronic device simulator (EDS) and MEMS bimorph cantilever beams (MBCB) array with beams lengths of 200, 250, and 300 μm that were tested to characterize deflection and thermal behavior. The specific beam lengths were chosen to actuate in response to heating associated with the EDS (i.e. the longest beams actuated first corresponding to the hottest portion of …
Mems-Based Terahertz Photoacoustic Chemical Sensing System, Nathan Glauvitz, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie
Mems-Based Terahertz Photoacoustic Chemical Sensing System, Nathan Glauvitz, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie
Electrical and Computer Engineering Faculty Research and Publications
Advancements in microelectromechanical system (MEMS) technology over the last several decades has been a driving force behind miniaturizing and improving sensor designs. In this work, a specialized cantilever pressure sensor was designed, modeled, and fabricated to investigate the photoacoustic (PA) response of gases to terahertz (THz) radiation under low-vacuum conditions associated with high-resolution spectroscopy. Microfabricated cantilever devices made using silicon-on-insulator (SOI) wafers were tested in a custom-built test chamber in this first ever demonstration of a cantilever-based PA chemical sensor and spectroscopy system in the THz frequency regime. The THz radiation source was amplitude modulated to excite acoustic waves in …
Analytical Modeling Of A Novel Microdisk Resonator For Liquid-Phase Sensing: An All-Shear Interaction Device (Asid), Mohamad Sadegh Sotoudegan
Analytical Modeling Of A Novel Microdisk Resonator For Liquid-Phase Sensing: An All-Shear Interaction Device (Asid), Mohamad Sadegh Sotoudegan
Dissertations (1934 -)
Extensive research on micro/nanomechanical resonators has been performed recently due to their potential to serve as ultra-sensitive devices in chemical/biosensing. These applications often necessitate liquid-phase sensing, introducing significant fluid-induced inertia and energy dissipation that reduces the resonator’s performance. To minimize the detrimental fluid effects on such devices, a novel microdisk resonator supported by two tangentially-oriented, axially-driven “legs” is investigated analytically and effects of the system parameters on the resonator/sensor performance are explored. Since the device surface vibrates primarily parallel to the fluid-structure interface, it is referred to here as an “all-shear interaction device,” or ASID. Analytical modeling of the ASID …
Thermal Microfluidic Devices; Design, Fabrication And Applications, Benyamin Davaji
Thermal Microfluidic Devices; Design, Fabrication And Applications, Benyamin Davaji
Dissertations (1934 -)
This thesis investigates the thermal actuation and temperature measurement methods in microfluidic devices. We designed and fabricated microfluidic devices with various functionalities such as: bio sensing, particle counting, microscale calorimetry, and cellular temperature measurement. All of these functionalities use thermal measurement methods. When quantitative measurements are required, the label-free nature of thermal measurement methods, along with its simple readout, make it a powerful candidate for lab on a chip and bio sensing/detection applications. In this work, thermal measurement methods are used to characterize bio-samples, measure concentrations, study thermal responses, and even perform particle cytometry. However, thermal measurement methods are known …
Improved Sensitivity Mems Cantilever Sensor For Terahertz Photoacoustic Spectroscopy, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie
Improved Sensitivity Mems Cantilever Sensor For Terahertz Photoacoustic Spectroscopy, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie
Electrical and Computer Engineering Faculty Research and Publications
In this paper, a microelectromechanical system (MEMS) cantilever sensor was designed, modeled and fabricated to measure the terahertz (THz) radiation induced photoacoustic (PA) response of gases under low vacuum conditions. This work vastly improves cantilever sensitivity over previous efforts, by reducing internal beam stresses, minimizing out of plane beam curvature and optimizing beam damping. In addition, fabrication yield was improved by approximately 50% by filleting the cantilever’s anchor and free end to help reduce high stress areas that occurred during device fabrication and processing. All of the cantilever sensors were fabricated using silicon-on-insulator (SOI) wafers and tested in a custom …
Design And Characterization Of A Low Cost Mems Imu Cluster For Precision Navigation, Daniel R. Greenheck
Design And Characterization Of A Low Cost Mems Imu Cluster For Precision Navigation, Daniel R. Greenheck
Master's Theses (2009 -)
The fast paced development of micro-electromechanical systems (MEMS) technology in recent years has resulted in the availability of low cost gyroscopes and accelerometers in commercial markets. These sensors can be integrated into a single device known as an inertial measurement unit (IMU). An IMU is capable of tracking and navigating a vehicle for a short period of time in the absence of external position and attitude updates. The precision of the manufacturing techniques used to fabricate commercial MEMS sensors as well as their mechanical nature result in noise and errors that limit their performance. It has been mathematically shown that …
Cantilever-Based Resonant Microsensors With Integrated Temperature Modulation For Transient Chemical Analysis, C. Carron, P. Getz, Stephen M. Heinrich, Fabien Josse, Oliver Brand
Cantilever-Based Resonant Microsensors With Integrated Temperature Modulation For Transient Chemical Analysis, C. Carron, P. Getz, Stephen M. Heinrich, Fabien Josse, Oliver Brand
Civil and Environmental Engineering Faculty Research and Publications
This work introduces a resonant cantilever platform with integrated temperature modulation for real-time chemical sensing. Embedded heaters allow for rapid thermal cycling of individual sensors, thereby enabling real-time transient signal analysis without the need for a microfluidic setup to switch between analyte and reference gases. Compared to traditional mass-sensitive microsensors operating in steady state, the on-chip generation of signal transients provides additional information for analyte discrimination.
Thermal Tuning Of Mems Buckled Membrane Actuator Stiffness, Robert A. Lake, Kyle K. Ziegler, Ronald A. Coutu Jr.
Thermal Tuning Of Mems Buckled Membrane Actuator Stiffness, Robert A. Lake, Kyle K. Ziegler, Ronald A. Coutu Jr.
Electrical and Computer Engineering Faculty Research and Publications
The thermal tuning characteristics of a microelectromechanical systems (MEMS) buckled membrane exhibiting regions of both positive and negative stiffness is examined and analyzed using finite element method (FEM) simulation and through experimentation. The membranes are fabricated by releasing a silicon/silicon dioxide (Si/SiO2) laminated membrane from a silicon on insulator (SOI) wafer. The difference in thermal expansion coefficients between Si and SiO2 induces a compressive stress in the SiO2 layer causing out-of-plane buckling of the membrane. This structure is found to have positive and negative stiffness regions when actuated with a transverse force. It is demonstrated that the …
Using Micro-Raman Spectroscopy To Assess Mems Si/Sio2 Membranes Exhibiting Negative Spring Constant Behavior, Lavern A. Starman, Ronald A. Coutu Jr.
Using Micro-Raman Spectroscopy To Assess Mems Si/Sio2 Membranes Exhibiting Negative Spring Constant Behavior, Lavern A. Starman, Ronald A. Coutu Jr.
Electrical and Computer Engineering Faculty Research and Publications
We introduce a novel micro-mechanical structure that exhibits two regions of stable linear positive and negative stiffness. Springs, cantilevers, beams and any other geometry that display an increasing return force that is proportional to the displacement can be considered to have a “Hookean” positive spring constant, or stiffness. Less well known is the opposite characteristic of a reducing return force for a given deflection, or negative stiffness. Unfortunately many simple negative stiffness structures exhibit unstable buckling and require additional moving components during deflection to avoid deforming out of its useful shape. In Micro-Electro-Mechanical Systems (MEMS) devices, buckling caused by stress …
Effect Of Hydrodynamic Force On Microcantilever Vibrations: Applications To Liquid-Phase Chemical Sensing, I. Dufour, E. Lemaire, B. Caillard, H. Debeda, C. Lucat, Stephen M. Heinrich, Fabien Josse, O. Brand
Effect Of Hydrodynamic Force On Microcantilever Vibrations: Applications To Liquid-Phase Chemical Sensing, I. Dufour, E. Lemaire, B. Caillard, H. Debeda, C. Lucat, Stephen M. Heinrich, Fabien Josse, O. Brand
Electrical and Computer Engineering Faculty Research and Publications
At the microscale, cantilever vibrations depend not only on the microstructure’s properties and geometry but also on the properties of the surrounding medium. In fact, when a microcantilever vibrates in a fluid, the fluid offers resistance to the motion of the beam. The study of the influence of the hydrodynamic force on the microcantilever’s vibrational spectrum can be used to either (1) optimize the use of microcantilevers for chemical detection in liquid media or (2) extract the mechanical properties of the fluid. The classical method for application (1) in gas is to operate the microcantilever in the dynamic transverse bending …
Influence Of Fluid-Structure Interaction On Microcantilever Vibrations: Applications To Rheological Fluid Measurement And Chemical Detection, Isabelle Dufour, E. Lemaire, B. Caillard, H. Debeda, C. Lucat, Stephen M. Heinrich, Fabien Josse, Oliver Brand
Influence Of Fluid-Structure Interaction On Microcantilever Vibrations: Applications To Rheological Fluid Measurement And Chemical Detection, Isabelle Dufour, E. Lemaire, B. Caillard, H. Debeda, C. Lucat, Stephen M. Heinrich, Fabien Josse, Oliver Brand
Civil and Environmental Engineering Faculty Research and Publications
At the microscale, cantilever vibrations depend not only on the microstructure’s properties and geometry but also on the properties of the surrounding medium. In fact, when a microcantilever vibrates in a fluid, the fluid offers resistance to the motion of the beam. The study of the influence of the hydrodynamic force on the microcantilever’s vibrational spectrum can be used to either (1) optimize the use of microcantilevers for chemical detection in liquid media or (2) extract the mechanical properties of the fluid. The classical method for application (1) in gas is to operate the microcantilever in the dynamic transverse bending …
Stress Monitoring Of Post-Processed Mems Silicon Microbridge Structures Using Raman Spectroscopy, Lavern A. Starman, Ronald A. Coutu Jr.
Stress Monitoring Of Post-Processed Mems Silicon Microbridge Structures Using Raman Spectroscopy, Lavern A. Starman, Ronald A. Coutu Jr.
Electrical and Computer Engineering Faculty Research and Publications
Inherent residual stresses during material deposition can have profound effects on the functionality and reliability of fabricated Micro-Electro-Mechanical Systems (MEMS) devices. Residual stress often causes device failure due to curling, buckling, or fracture. Typically, the material properties of thin films used in surface micromachining are not well controlled during deposition. The residual stress; for example, tends to vary significantly for different deposition methods. Currently, few nondestructive techniques are available to measure residual stress in MEMS devices prior to the final release etch. In this research, micro-Raman spectroscopy is used to measure the residual stresses in polysilicon MEMS microbridge devices. This …
Srrs Embedded With Mems Cantilevers To Enable Electrostatic Tuning Of The Resonant Frequency, E. A. Moore, Derrick Langley, Matthew E. Jussaume, L. A. Rederis, C. A. Lundell, Ronald A. Coutu Jr., Peter J. Collins, Lavern A. Starman
Srrs Embedded With Mems Cantilevers To Enable Electrostatic Tuning Of The Resonant Frequency, E. A. Moore, Derrick Langley, Matthew E. Jussaume, L. A. Rederis, C. A. Lundell, Ronald A. Coutu Jr., Peter J. Collins, Lavern A. Starman
Electrical and Computer Engineering Faculty Research and Publications
A microelectromechanical systems (MEMS) cantilever array was monolithically fabricated in the gap region of a split ring resonator (SRR) to enable electrostatic tuning of the resonant frequency. The design consisted of two concentric SRRs each with a set of cantilevers extending across the split region. The cantilever array consisted of five beams that varied in length from 300 to 400 μm, with each beam adding about 2 pF to the capacitance as it actuated. The entire structure was fabricated monolithically to reduce its size and minimize losses from externally wire bonded components. The beams actuate one at a time, longest …
A Mems Photoacoustic Detector Of Terahertz Radiation For Chemical Sensing, Nathan Glauvitz, S. Blazevic, Ronald A. Coutu Jr., Michael Kistler, Ivan R. Medvedev, Douglas T. Petkie
A Mems Photoacoustic Detector Of Terahertz Radiation For Chemical Sensing, Nathan Glauvitz, S. Blazevic, Ronald A. Coutu Jr., Michael Kistler, Ivan R. Medvedev, Douglas T. Petkie
Electrical and Computer Engineering Faculty Research and Publications
A piezoelectric Microelectromechanical system (MEMS) cantilever pressure sensor was designed, modeled, fabricated, and tested for sensing the photoacoustic response of gases to terahertz (THz) radiation. The sensing layers were comprised of three thin films; a lead zirconate titanate (PZT) piezoelectric layer sandwiched between two metal contact layers. The sensor materials were deposited on the silicon device layer of a silicon-on-insulator (SOI) wafer, which formed the physical structure of the cantilever. To release the cantilever, a hole was etched through the backside of the wafer and the buried oxide was removed with hydrofluoric acid. Devices were then tested in a custom …
Effects Of Su-8 Cross-Linking On Flip-Chip Bond Strength When Assembling And Packaging Mems, Nathan E. Glavitz, Lavern A. Starman, Ronald A. Coutu Jr., Richard L. Johnson
Effects Of Su-8 Cross-Linking On Flip-Chip Bond Strength When Assembling And Packaging Mems, Nathan E. Glavitz, Lavern A. Starman, Ronald A. Coutu Jr., Richard L. Johnson
Electrical and Computer Engineering Faculty Research and Publications
New methods to assemble, integrate, and package micro devices are always needed in attempts to simplify and expedite fabrication methods to maximize throughput. Our paper focuses on assessing SU-8 as a viable material for packaging and flip chip bonding processes for MEMS and micro devices. In this paper, we vary the level of cross- linking through post exposure bake (PEB) times and assess rectangular ring test structures bonding strength following flip chip bonding through applied tensile loads. In addition, we performed initial assessments on the etching resiliency of varied cross-linking of SU-8. From initial results, the bonding strength is maximized …
A Comparison Of Micro-Switch Analytic, Finite Element, And Experimental Results, Ronald A. Coutu Jr., P. E. Kladitis, Lavern A. Starman, J. R. Reid
A Comparison Of Micro-Switch Analytic, Finite Element, And Experimental Results, Ronald A. Coutu Jr., P. E. Kladitis, Lavern A. Starman, J. R. Reid
Electrical and Computer Engineering Faculty Research and Publications
Electrostatically actuated, metal contact, micro-switches depend on having adequate contact force to achieve desired, low contact resistance. In this study, higher contact forces resulted from overdriving cantilever beam style switches, after pull-in or initial contact, until the beam collapsed onto the drive or actuation electrode. The difference between initial contact and beam collapse was defined as the useful contact force range. Micro-switch pull-in voltage, collapse voltage, and contact force predictions, modeled analytically and with the CoventorWare finite element software package, were compared to experimental results. Contact resistance was modeled analytically using Maxwellian spreading resistance theory. Contact resistance and contact …