Engineering Commons^™

Investigating Mems Devices In Flow Conditions Relevant To Flow-Through Systems., Mohammad Shafquatul Islam

Electronic Theses and Dissertations

Advancements in microscale actuating technologies has substantially expanded the possibilities of interacting with the surrounding environment. Microstructures that deflect in response to mechanical forces are one of the largest application areas of microelectromechanical systems (MEMS). MEMS devices, functioning as sensors, actuators, and support structures, find applications in inertial sensors, pressure sensors, chemical sensors, and robotics, among others. Driven by the critical role of catalytic membrane reactors, this dissertation aims to evaluate enzyme activity on polymeric membranes and explore how fabrication methods from the field of Electrical and Computer Engineering (ECE) can incorporate sensing and actuation into these porous surfaces. Toward …

Modeling, Simulation And Control Of Microrobots For The Microfactory., Zhong Yang

Electronic Theses and Dissertations

Future assembly technologies will involve higher levels of automation in order to satisfy increased microscale or nanoscale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to the microelectronics and MEMS industries, but less so in nanotechnology. With the boom of nanotechnology since the 1990s, newly designed products with new materials, coatings, and nanoparticles are gradually entering everyone’s lives, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than top-down robotic assembly. This is due to considerations of volume handling of large …

Feasibility Study Of Radio Frequency Microelectromechanical Filters For Space Operation, Karanvir Singh

Theses and Dissertations

Piezoelectric contour mode resonator technology has the unique advantage of combining low motional resistance with the ability to define multiple frequencies on the same substrate. Contour mode resonators can be mechanically coupled together to form robust band-pass filters for the next generation of GPS satellites with extreme size reduction compared to electrically coupled filters. Piezoelectric zinc oxide (ZnO) contour mode resonators have the potential for monolithic integration with current ZnO transistor further reducing size, power consumption, and cost of filter modules. Barium strontium titanate (BST) contour mode resonators have incredible frequency tunability due to the fundamental nature of the thin …

Mems Directional Acoustic Sensors, Colby Damren

Thinking Matters Symposium

The purpose of my project is to test and verify two Micro-Electro-Mechanical-System (MEMS) microphones. The two MEMS devices are biomimetic microphones that imitate the eardrums of the Ormia Ochracea, a parasitic fly that listens for host crickets to lay their eggs. The MEMS microphones mimic the eardrum spacing of the Ormia Ochracea with a spacing of 1000um. This is roughly twice the opening of the Ormia Ochracea. The microphones will be tested for directionality inside a wooden box. This box will be lined with beveled foam to prevent any echo or outside noise from interfering with the results. These results …

Design, Simulation And Testing Of Biomimetic Directional Acoustic Sensors, Brendan Francis

Thinking Matters Symposium

The Ormia ochracea, a species of parasitic fly, has become the focal point in sound localization research because of its finely tuned hearing abilities. The female of this species uses its super highly directional hearing to pinpoint the call of a host cricket, with hypersensitivity of frequency and phase difference, to reach and dispose of its eggs on the host. The goal of this study was to further the research of a previous Project in Professor Guvench’s group which implemented MEMS (Micro Electro-Mechanical System) technology on a chip to replicate these abilities. In this iteration, however, some commercially available …

Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for silicon microneedle arrays to extract dermal interstitial fluid (ISF) from human skin. ISF is a cell- free, living tissue medium that is known to contain many of the same, clinical biomarkers of general health, stress response and immune status as in blood. However, a significant barrier to adoption of ISF as a diagnostic matrix is the lack of a rapid, minimally invasive method of access and collection for analysis. Microfabricated chips containing arrays of microneedles that can rapidly and painlessly access and collect dermal ISF for …

Microrobots For Wafer Scale Microfactory: Design Fabrication Integration And Control., Ruoshi Zhang

Electronic Theses and Dissertations

Future assembly technologies will involve higher automation levels, in order to satisfy increased micro scale or nano scale precision requirements. Traditionally, assembly using a top-down robotic approach has been well-studied and applied to micro-electronics and MEMS industries, but less so in nanotechnology. With the bloom of nanotechnology ever since the 1990s, newly designed products with new materials, coatings and nanoparticles are gradually entering everyone’s life, while the industry has grown into a billion-dollar volume worldwide. Traditionally, nanotechnology products are assembled using bottom-up methods, such as self-assembly, rather than with top-down robotic assembly. This is due to considerations of volume handling …

Parylene Based Flexible Multifunctional Biomedical Probes And Their Applications, Zhiguo Zhao

Wayne State University Dissertations

MEMS (Micro Electro Mechanical System) based flexible devices have been studied for decades, and they are rapidly being incorporated into modern society in various forms such as flexible electronics and wearable devices. Especially in neuroscience, flexible interfaces provide tremendous possibilities and opportunities to produce reliable, scalable and biocompatible instruments for better exploring neurotransmission and neurological disorders. Of all the types of biomedical instruments such as electroencephalography (EEG) and electrocorticography (ECoG), MEMS-based needle-shape probes have been actively studied in recent years due to their better spatial resolution, selectivity, and sensitivity in chronical invasive physiology monitoring. In order to address the inherent …

Development Of A Mems Fabrication Process On Soi To Study High Strain In Transition-Metal Dichalcogenides, Edgar Acosta

Open Access Theses & Dissertations

Over the recent years there has been an increasing demand of better performing electronics. However, as the semiconductor industry keeps on improving and scaling the technology to the nanometer regime, the passive power density has overcome the overall power consumption of transistors. The inability to reduce the power alongside the scaling of transistors has led the scientific community in the search for alternatives or different solutions to overcome this power crisis. The use of two-dimensional Transition-Metal Dichalcogenides (TMDCS) and Micro-Electro-Mechanical System (MEMS) actuators, in conjunction, has been proposed as an alternative solution [1]. Recent studies of TMDCS have shown a …

Solarpede: An Untethered Micro Robot Powered By Light., Jordan Fredrick Klotz

Electronic Theses and Dissertations

Micro-Robotics looks to implement robotics principles at a small scale and has gained popularity in recent decades as a gateway to new research areas such as micro-factory applications. The SolarPede is a second-generation, cm-scale micro-crawler designed for such micro factory applications which is equipped with a legged locomotion system and an electronic backpack. The SolarPede is an evolution of its predecessors and features power and signal conditioning capabilities, gait pattern generation, and Bluetooth connectivity. The components which make up SolarPede have been full validated and tested, and its systems have been realized in the form of a body made from …

Conductivity Modulation In Strained 2d Transition- Metal- Dichalcogenides Via Micro- Electro- Mechanical Actuation, Aldo Ivan Vidaña

Open Access Theses & Dissertations

In this thesis, strain-induced conductivity modulation in bi-layer molybdenum disulfide (MoS2) flakes is experimentally investigated and modeled. Uniaxial tensile strain in the MoS2 flakes is achieved using a micro-electro-mechanical (MEM) actuator. Conductivity ratios up to 400 are demonstrated. Theoretical predictions of conductivity versus applied voltage in the MEMS-MoS2 device match experimental data reasonably well using only the effective width of the TMDC flakes as the sole fitting parameter. The amount of strain induced in the MoS2 flakes was determined to be as high as 2.7% for one flake using the model fitted to the experiment data. The switching energy required …

Exploration Of Radiation Damage Mechanism In Mems Devices., Pranoy Deb Shuvra

Electronic Theses and Dissertations

We explored UV, X-ray and proton radiation damage mechanisms in MEMS resonators. T-shaped MEMS resonators of different dimensions were used to investigate the effect of radiation. Radiation damage is observed in the form of resistance and resonance frequency shift of the device. The resistance change indicates a change in free carrier concentration and mobility, while the resonance frequency change indicates a change in mass and/or elastic constant. For 255nm UV radiation, we observed a persistent photoconductivity that lasts for about 60 hours after radiation is turned off. The resonance frequency also decreases 40-90 ppm during irradiation and slowly recovers at …

Mems Variable Area Capacitor For Room Temperature Electrometry, George C. Underwood, Tod V. Laurvick

Faculty Publications

This paper introduces a new way to detect charge using MEMS variable capacitors for extremely sensitive, room temperature electrometry. It is largely based on the electrometers introduced by Riehl et al. [1] except variable capacitance is created by a changing area, not a changing gap. The new scheme will improve MEMS electrometers by eliminating the effects of squeeze-film damping and by theoretically increasing the maximum charge resolution by 70%. The charge conversion gain (the increase in output voltage per input unit charge) for this system is derived. The result show good agreement with MATLAB calculations.

Applications Of Polarized Metallic Nanostructures., Jasmin Beharic

Electronic Theses and Dissertations

Gold nanostructures exhibit technologically useful properties when they are polarized in an electric field. In two projects we explore instances where the polarized metal can be used in real world applications. The first project involves gold nanoparticles (GNP) for use in light actuated microelectromechanical systems (MEMS) applications. Although the GNPs were originally designed for volumetric heating in biomedical applications, we treat them as a thin film coating, opening the door for these particles to be used in MEMS applications. This work characterizes the thermal properties of gold nanoparticles on surfaces for spatially-targeted thermal actuation in MEMS systems. The second project …

Pvdf-Trfe Electroactive Polymer Mechanical-To-Electrical Energy Harvesting Experimental Bimorph Structure, William G. Kaval, Robert A. Lake, Ronald A. Coutu Jr.

Faculty Publications

Research of electrostrictive polymers has generated new opportunities for harvesting energy from the surrounding environment and converting it into usable electrical energy. Electroactive polymer (EAP) research is one of the new opportunities for harvesting energy from the natural environment and converting it into usable electrical energy. Piezoelectric ceramic based energy harvesting devices tend to be unsuitable for low-frequency mechanical excitations such as human movement. Organic polymers are typically softer and more flexible therefore translated electrical energy output is considerably higher under the same mechanical force. In addition, cantilever geometry is one of the most used structures in piezoelectric energy harvesters, …

Design, Modeling, Fabrication, And Testing Of A Multistage Micro Gas Compressor With Piezoelectric Unimorph Diaphragm And Passive Microvalves For Microcooling Applications, Shawn Thanhson Le

Doctoral Dissertations

This dissertation investigates the development of a multistage micro gas compressor utilizing multiple pump stages cascaded in series to increase the pressure rise with passive microvalves and piezoelectric unimorph diaphragms. This research was conducted through modeling, simulation, design, and fabrication of the microcompressor and its components. A single-stage and a two-stage microcompressor were developed to demonstrate and compare the performance and effectiveness of using a cascaded multistage design.

Steady fluid flow through static microvalves structure was studied to gain insight on its gas flow dynamics and characteristics. Transient analysis combined with the structure's interaction was investigated with an analytical model …

Strategies And Techniques For Fabricating Mems Bistable Thermal Actuators., Dilan Ratnayake

Electronic Theses and Dissertations

Bistable elements are beginning to appear in the field of MEMS as they allow engineers to design sensors and actuators which require no electrical power and possess mechanical memory. This research focuses on the development of novel strategies and techniques for fabricating MEMS bistable structures to serve as no electrical power thermal actuators. Two parallel strategies were explored for the design and fabrication of the critical bistable element. Both strategies involved an extensive material study on candidate thin film materials to determine their temperature coefficient of expansion and as-deposited internal stress properties. Materials investigated included titanium tungsten, Invar, silicon nitride …

Selective Resistive Sintering: A Novel Additive Manufacturing Process, Austin Bryan Van Horn

Graduate Theses and Dissertations

Selective laser sintering (SLS) is one of the most popular 3D printing methods that uses a laser to pattern energy and selectively sinter powder particles to build 3D geometries. However, this printing method is plagued by slow printing speeds, high power consumption, difficulty to scale, and high overhead expense. In this research, a new 3D printing method is proposed to overcome these limitations of SLS. Instead of using a laser to pattern energy, this new method, termed selective resistive sintering (SRS), uses an array of microheaters to pattern heat for selectively sintering materials. Using microheaters offers significant power savings, significantly …

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 …

Thermal Management Using Mems Bimorph Cantilever Beams, Ronald A. Coutu Jr., Robert S. Lafleur, John P. Walton, Laverne A. Starman

Faculty 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

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 …

Handcrafted Electrocorticography Electrodes For A Rodent Behavioral Model, Nishat Tasnim, Ali Ajam, Raul Ramos, Mukhesh K. Koripalli, Manisankar Chennamsetti, Yoonsu Choi

Electrical and Computer Engineering Faculty Publications and Presentations

Electrocorticography (ECoG) is a minimally invasive neural recording method that has been extensively used for neuroscience applications. It has proven to have the potential to ease the establishment of proper links for neural interfaces that can offer disabled patients an alternative solution for their lost sensory and motor functions through the use of brain-computer interface (BCI) technology. Although many neural recording methods exist, ECoG provides a combination of stability, high spatial and temporal resolution with chronic and mobile capabilities that could make BCI systems accessible for daily applications. However, many ECoG electrodes require MEMS fabricating techniques which are accompanied by …

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydrocephalus is a neurological disorder that typically requires a long-term implantation of a shunt system to manage its symptoms. These shunt systems are notorious for their extremely high failure rate. More than 40% of all implanted shunt systems fail within the first year of implantation. On average, 85% of all hydrocephalus patients with shunt systems undergo at least two shunt-revision surgeries within 10 years of implantation. A large portion of this high failure rate can be attributed to biofouling-related obstructions and infections. Previously, we developed flexible polyimide-based magnetic microactuators to remove obstructions formed on hydrocephalus shunts. To test the long-term …

Microfluidics, Armando P. Carreon Romero

BYU Research Development Office Research Networking Conference

his research focuses on leveraging micro and nanofabrication techniques to develop advanced microfluidic devices and systems. These innovations hold promise for a wide range of applications, from biomedical diagnostics to environmental monitoring and optical communications.

Variable Response Of A Thermally Tuned Mems Pressure Sensor, Robert A. Lake, Ronald A. Coutu Jr.

Faculty Publications

A typical microelectromechanical systems (MEMS) pressure sensor consists of a thin, deformable membrane and sensing element such as a piezoresistive element which is used to measure the amount of deflection in response to an applied pressure. Previous efforts demonstrated that buckled membranes, from silicon on insulator (SOI) wafers, can be thermally tuned via joule heating. By applying heat to the membrane through a resistive heating element, compressive stress is induced in the membrane causing it to buckle further out of plane and increasing its overall stiffness response. It is demonstrated that by increasing the stiffness of the membrane, the response …

Ultra-Thin Aluminum Nitride Thin Films For Flexible Mems Sensors, Md Sajeeb Rayhan

Electrical Engineering Dissertations

Microelectromechanical systems (MEMS) sensors using ultrathin aluminum nitride (AlN) film were developed and fabricated using conventional photolithography techniques in the class 100 clean room with a view to integrate them in flexible substrates along with flexible electronics. The MEMS sensors were designed, analytically modeled, fabricated and characterized. Some of the MEMS sensors were only designed and simulated using finite element method (FEM) for the scope of the dissertation. These MEMS sensors can be applied to many applications such as automobile, robotics, biomedical, biometrics, health condition monitoring, GPS tracking devices, smartphones and aircrafts. MEMS pressure sensors using AlN based piezoelectric film …

Improved Sensitivity Mems Cantilever Sensor For Terahertz Photoacoustic Spectroscopy, Ronald A. Coutu Jr., Ivan R. Medvedev, Douglas T. Petkie

Faculty 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 …

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

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.