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Design, Fabrication, And Testing Of A 3d Printer Based Microfluidic System, Carlton A. Mcmullen

Graduate Theses and Dissertations

A pneumatically actuated PDMS based microfluidic devices were designed and fabricated by soft-lithography. Two types of molds were fabricated out of different material for this experiment. The first mold, (device 1), was fabricated from a sheet of Polymethyl methacrylate (PMMA) material, similar to Plexiglas. The device features were micro-engraved onto the face of the material. The second mold, (device 2), was fabricated from the use of fused deposition modeling (FDM) 3D printing. The pumping efficiency of the PDMS devices was analyzed through the characterization of the micro-pumps flowrate with respect to the pumps driving pressure and the actuation frequency. Tested …

Combining In Situ Tensile Testing And Orientation Microscopy In The Sem: A Mems Based Setup For Studying Time Dependent Deformation Of Thin Films By Tkd And Stem, Jan Philipp Liebig, Benoit Merle, Mathias Goken

Nanomechanical Testing in Materials Research and Development V

Structures in integrated devices are constantly subjected to residual or thermal stresses during operation. Understanding the relaxation behavior of thin films is therefore critical for improving their reliability.

Recently it was shown that Transmission Kikuchi Diffraction (TKD) in the Scanning Electron Microscope (SEM) enables the determination of local crystal orientations with high spatial resolution using standard Electron Backscatter Diffraction (EBSD) instrumentation [1, 2]. Giving access to quantitative information on mechanisms like grain growth, grain rotation and strain gradient evolution, time resolved TKD stands out as a promising technique for the characterization of microstructural changes upon relaxation of thin films.

We …

Stochastic Stability And Uncertainty Quantification Of Ring-Based Vibratory Gyroscopes, Soroush Arghavan

Electronic Thesis and Dissertation Repository

Effect of stochastic fluctuations in angular velocity on the stability of two DOF ring-type MEMS gyroscopes is investigated. The governing Stochastic Differential Equations are discretized using the higher-order Milstein scheme in order to numerically predict the system response assuming the fluctuations to be white noise. Simulations via Euler scheme as well as a measure of Largest Lyapunov Exponents are employed for validation purposes due to lack of similar analytical or experimental data. The stability investigation predicts that the threshold fluctuation intensity increases nonlinearly with damping ratio. Under typical gyroscope operating conditions, nominal input angular velocity magnitude and mass mismatch appear …

Securemems: Selective Deposition Of Energetic Materials, Trevor J. Fleck, Josiah R. Thomas, Lillian F. Miles, Allison K. Murray, Zane A. Roberts, Raghav Ramachandran, I Emre Gunduz, Steven F. Son, George T. Chiu, Jeffrey F. Rhoads

The Summer Undergraduate Research Fellowship (SURF) Symposium

There exists a pressing operational need to secure and control access to high-valued electromechanical systems, and in some cases render them inoperable. Developing a reliable method for depositing energetic materials will allow for the near-seamless integration of electromechanical systems and energetic material, and, in turn, provide the pathway for security and selective destruction that is needed. In this work, piezoelectric inkjet printing was used to selectively deposit energetic materials. Nanothermites, comprising of nanoscale aluminum and nanoscale copper oxide suspended in dimethyl-formamide (DMF), were printed onto silicon wafers, which enabled both thermal and thrust measurements of the decomposing energetic material. Various …

A Wireless Communication Platform For Mems Sensors, Chen Chen

Theses

Wireless measurement systems combining current advanced information collection, processing and wireless communication technology, have been applied to information measurement in special occasions. As a short range wireless communication technology, bluetooth is low cost, stable, and low power. Bluetooth technology is used in monitoring and wireless control system widely.

ArduinoBT is the bluetooth version of the general Arduino board, which is open source and convenient as a wireless development tool.

This thesis presents a hardware and software experimental wireless platform for the application of multiple kinds of MEMS sensors. By the combination of ArduinoBT and signal conditioning circuit, different types of …

A Resonant Based Test Methodology For Capacitive Mems, Ali Dianat

Electronic Theses and Dissertations

This work presents a test method for capacitive Micro-Electro-Mechanical Systems (MEMS). A major class of MEMS sensors operate based on the principle of capacitance variation.The proposed test method in this work utilizes a resonant circuit to detect structural defects of capacitive MEMS sensors. It is shown that a small variation of MEMS capacitance due to a defect alters the resonance frequency considerably. It is also shown that the variation of the output amplitude can be observed for fault detection if an inductor with a high quality factor is employed in the test circuit. Mathematical approach is taken and verified to …

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 …

Sensor Fusion For Effective Hand Motion Detection, Fatemeh Abyarjoo

FIU Electronic Theses and Dissertations

No abstract provided.

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.

Micro Electrostatic Actuation Of A Silicon Diaphragm, Matthew W. Samples

Master's Theses

There are a number of applications, from hearing aids to microfluidic pumps, which utilize micro-scale actuating diaphragms. These MEMS (micro-electromechanical system) devices can be actuated by electrostatic forces, which utilize an induced electric field to pull two charged plates towards one another. Such devices were fabricated and electrostatic actuation of the diaphragms was performed to analyze its viability as a micro-speaker. The long-term performance of such products requires adequate diaphragm deflection to create audible pressure waves with relatively low maximum stresses to ensure a high cycle fatigue life. With these requirements, initial calculations and FEA (finite element analysis) were performed …

Aluminum Nitride Contour Mode Resonators, Joshua Robert Melnick

Theses

Resonators are a major component in RF electronic products. They are used in a host of ways to filter radio signals. Modern and Future RF communications have placed high demands on the industry; requiring low power usage, wide array of applications and resistance to noise.

In this thesis, a discussion of the motivation for RF MEMS filters and basic theory is given with an explanation of the concepts of Q factor, piezoelectricity, acoustics theory, the major types of resonators (SAW, BAW, CMR or LAMB), apodization theory and techniques as well as design, simulation of CMR and BAW devices, testing and …

Cmos Compatible 3-Axis Magnetic Field Sensor Using Hall Effect Sensing, Joshua R. Locke

Theses

The purpose of this study is to design, fabricate and test a CMOS compatible 3-axis Hall effect sensor capable of detecting the earth’s magnetic field, with strength’s of ~50 μT. Preliminary testing of N-well Van Der Pauw structures using strong neodymium magnets showed proof of concept for hall voltage sensing, however, poor geometry of the structures led to a high offset voltage. A 1-axis Hall effect sensor was designed, fabricated and tested with a sensitivity of 1.12x10-3 mV/Gauss using the RIT metal gate PMOS process. Poor geometry and insufficient design produced an offset voltage of 0.1238 volts in the 1-axis …

Characterization Of Mechanical Properties At The Micro/Nano Scale: Stiction Failure Of Mems, High-Frequency Michelson Interferometry And Carbon Nanofibers, Arash Kheyraddini Mousavi

Mechanical Engineering ETDs

Different forces scale differently with decreasing length scales. Van der Waals and surface tension are generally ignored at the macro scale, but can become dominant at the micro and nano scales. This fact, combined with the considerable compliance and large surface areas of micro and nano devices, can leads to adhesion in MicroElectroMechanical Systems (MEMS) and NanoElectroMechanical Systems (NEMS) - a.k.a. stiction-failure. The adhesive forces between MEMS devices leading to stiction failure are characterized in this dissertation analytically and experimentally. Specifically, the adhesion energy of poly-Si μcantilevers are determined experimentally through Mode II and mixed Mode I&II crack propagation experiments. …

Microscale Radiometer Based On The Knudsen Thermal Force, Andrew Strongrich

Open Access Theses

Radiometric phenomena arise in non-isothermal rarefied gas flows for which the molecular mean-free path is approximately equal to the characteristic scale of the temperature gradient. The non-equilibrium nature of these flows results in thermal stresses which are capable of exerting forces and moments on immersed structures. When the stresses are established between unequally heated bodies the forces are referred to as Knudsen thermal forces. This work presents the design, fabrication, and characterization of a novel in-plane microscale radiometer capable of both producing and resolving Knudsen forces in low pressures. The current work differs from previous implementations in that both capacitance …

Heat And Mass Transfer Analysis Of A Film Evaporative Mems Tunable Array, William John O'Neill

Open Access Theses

This thesis details the heat and mass transfer analysis of a MEMs microthruster designed to provide propulsive, attitude control and thermal control capabilities to a cubesat. This thruster is designed to function by retaining water as a propellant and applying resistive heating in order to increase the temperature of the liquid-vapor interface to either increase evaporation or induce boiling to regulate mass flow. The resulting vapor is then expanded out of a diverging nozzle to produce thrust. Because of the low operating pressure and small length scale of this thruster, unique forms of mass transfer analysis such as non-continuum gas …

Modeling Of The Response Of A Memcapacitor For An Impulse, Step, Ramp, And Sinusiodal Inputs, Ghassan Khalil Kachmar

Open Access Theses & Dissertations

Micro-Electro-Mechanical Systems, or MEMS, is a technology of very small scale devices. The dimensions of MEMS can vary from below one micron to several millimeters. MEMS have some mechanical functionalities such as the moving plate of a parallel plate capacitor (memcapacitor). MEMS researchers and developers have demonstrated an extremely large number of microsensors for almost every possible sensing modality including temperature, pressure, inertial forces, and chemical species. The equation of motion of the moving plate of a memcapacitor is governed by a non-linear differential equation with no known exact solution. Most research into determining the theoretical response of a memcapacitor …