<div><p>Analyzing behaviors of objects on the road is a complex task that requires data from various sensors and their fusion to recreate movement of objects with a high degree of accuracy. A data collection and processing system are thus needed to track the objects accurately in order to make an accurate and clear map of the trajectories of objects relative to various coordinate frame(s) of interest in the map. Detection and tracking moving objects (DATMO) and Simultaneous localization and mapping (SLAM) are the tasks that needs to be achieved in conjunction to create a clear map of the road comprising of the moving and static objects.</p> <p> These computational problems are commonly solved and used to aid scenario reconstruction for the objects of interest. The tracking of objects can be done in various ways, utilizing sensors such as monocular or stereo cameras, Light Detection and Ranging (LIDAR) sensors as well as Inertial Navigation systems (INS) systems. One relatively common method for solving DATMO and SLAM involves utilizing a 3D LIDAR with multiple monocular cameras in conjunction with an inertial measurement unit (IMU) allows for redundancies to maintain object classification and tracking with the help of sensor fusion in cases when sensor specific traditional algorithms prove to be ineffectual when either sensor falls short due to their limitations. The usage of the IMU and sensor fusion methods relatively eliminates the need for having an expensive INS rig. Fusion of these sensors allows for more effectual tracking to utilize the maximum potential of each sensor while allowing for methods to increase perceptional accuracy. </p> <p>The focus of this thesis will be the dock-less e-scooter and the primary goal will be to track its movements effectively and accurately with respect to cars on the road and the world. Since it is relatively more common to observe a car on the road than e-scooters, we propose a data collection system that can be built on top of an e-scooter and an offline processing pipeline that can be used to collect data in order to understand the behaviors of the e-scooters themselves. In this thesis, we plan to explore a data collection system involving a 3D LIDAR sensor and multiple monocular cameras and an IMU on an e-scooter as well as an offline method for processing the data to generate data to aid scenario reconstruction. </p><br></div>

Die vorliegende Arbeit befasst sich mit der Methode der modalen Superposition als Ordnungsreduktionsverfahren in der Mikrosystemtechnik. Typische Anwendungsgebiete sind Inertialsensoren und dabei im Besonderen Drehratensensoren, für die die Simulation von zeitabhängigen Phänomenen von entscheidender Bedeutung ist. Im Rahmen der Weiterentwicklung der Ordnungsreduktion nach der Methode der modalen Superposition ist es gelungen für typische lineare Kräfte eine auf analytischen Gleichungen basierende Beschreibung im reduzierten Raum zu finden. Für die Beschreibung von nichtlinearen Kräften ist im Rahmen dieser Arbeit ein Verfahren entwickelt worden, das es erlaubt, bestehende Modelle im Finite-Elemente-Raum in der modalen Beschreibung zu nutzen. In dieser Arbeit werden die theoretischen Grundlagen zur Berücksichtigung von Einflüssen der Aufbau- und Verbindungstechnik in ordnungsreduzierten Modellen dargestellt. Neben der Einkopplung äußerer Kräfte und der Veränderung der mechanischen Randbedingungen wird auch der Einfluss der Aufbau- und Verbindungstechnik auf die elektrostatischen Eigenschaften untersucht. Die Parametrisierung des Verfahrens der modalen Superposition über Fit- und Interpolationsverfahren erlaubt es, parametrisierte ordnungsreduzierte Modelle für die zeitabhängige Systemsimulation zu generieren. Damit wird die Durchführung von Designoptimierung und die Berücksichtigung von Fertigungs- und Prozessschwankungen in ordnungsreduzierten Modellen auf Systemebene möglich.

<p>To facilitate indoor air quality (IAQ) monitoring, the research described herein develops and implements methods for the electronic integration of two types of gas sensor, each functionalized with a polymer blend tailored for CO₂ detection. A highly sensitive and tunable electronic chemiresistive sensor interface was developed and experimentally validated. This device achieved analog-to-digital conversion (ADC) through a pulse width modulated (PWM) signal, temporary data storage with an efficient data buffering system, and noise reduction and signal amplification utilizing an instrumentation amplifier integrator circuit. These techniques can used beyond CO₂-specific applications to compensate for certain undesirable chemiresistive sensor characteristics, such as low response magnitude and signal noise. Additionally, resonant mass sensing circuitry was combined with an on-chip field programmable gate array (FPGA) implemented frequency counter. Hz-level resolution was achieved with an Alorium Snō FPGA board and a Verilog data acquisition and communication program. This device can monitor up to 16 sensor channels simultaneously and has a straightforward interface with a controllable output. Furthermore, the functionality of each integrated sensor was experimentally validated. With additional work, these integrated designs have the potential to be inexpensive, low-power, highly sensitive devices that are suitable for practical use in IAQ monitoring applications.</p>

FeCrAl alloys are being investigated as candidate materials for replacing zirconium based alloys as nuclear reactor fuel cladding because of their superior high temperature oxidation resistance in steam environments. Unirradiated FeCrAl as well as Fe²⁺ ion irradiated FeCrAl to a peak dose of 20DPA were mechanically tested and compared against each other. Nanohardness tests were performed on both the unirradiated and irradiated conditions and it was found that the irradiated alloy was about 1GPa harder than its unirradiated counterpart. TEM <i>in situ</i> tensile tests were performed using the Bruker push to pull device alongside a PI95 Picoindenter on single crystals with grain orientations 001, 011 and 111. The unirradiated 001 grains tended to fail without yielding in a brittle manner while the irradiated 001 grain yielded and reached an ultimate tensile strength before failure. The unirradiated 011 grains behaved in a mixed manner, where one failed without yielding and one slipped many times before failing. The irradiated 011 grain yielded and failed quickly thereafter. The unirradiated 111 grain yielded, slipped and twinned before failing and both irradiated 111 grains slipped. Two general trends were observed. One, each unirradiated single grain was stronger than its irradiated counterpart. This trend is indicative of the ion irradiated microstructure facilitating bulklike mechanical behavior in the irradiated samples whereas the unirradiated samples exhibited mechanical size effects due to either the total lack of preexisting defects or the ability for existing defects to escape easily to the surface of the sample resulting in a pristine, defect free sample. Two, regardless of irradiation condition, the 001 grain orientation was brittle, the 011 grain orientation deformed in a mixed brittle/ductile manner and the 111 grain orientation was ductile through all tests. These results are indicative of the geometry of the BCC crystal structure and the slip system involving these orientations.

This paper presents the design, simulation, assembly and testing of a force-compensated hydrogel-based pH sensor. In the conventional deflection method, a piezoresistive pressure sensor is used as a chemical-mechanical-electronic transducer to measure the volume change of a pH-sensitive hydrogel. In this compensation method, the pH-sensitive hydrogel keeps its volume constant during the whole measuring process, independent of applied pH value. In order to maintain a balanced state, an additional thermal actuator is integrated into the close-loop sensor system with higher precision and faster dynamic response. Poly (N-isopropylacrylamide) (PNIPAAm) with 5 mol% monomer 3-acrylamido propionic acid (AAmPA) is used as the temperature-sensitive hydrogel, while poly (vinyl alcohol) with poly (acrylic acid) (PAA) serves as the pH-sensitive hydrogel. A thermal simulation is introduced to assess the temperature distribution of the whole microsystem, especially the temperature influence on both hydrogels. Following tests are detailed to verify the working functions of a sensor based on pH-sensitive hydrogel and an actuator based on temperature-sensitive hydrogel. A miniaturized prototype is assembled and investigated in deionized water: the response time amounts to about 25 min, just half of that one of a sensor based on the conventional deflection method. The results confirm the applicability of the compensation method to the hydrogel-based sensors.

Dans le cadre de la thèse des modèles physico-mathématiques pour des microsystèmes électromécaniques avec une permittivité générale sont développés et analysés par des méthodes mathématiques modernes du domaine des équations aux dérivées partielles. En particulier ces systèmes sont à frontière libre et pour conséquence difficiles à traiter. Des méthodes numériques ont été développées pour valider les résultats analytiques obtenus. / In the framework of this thesis physical/mathematical models for microelectromechanical systems with general permittivity have been developed and analysed with modern mathematical methods from the domain of partial differential equations. In particular these systems are moving boundary problems and thus difficult to handle. Numerical methods have been developed in order to validate the obtained analytical results.

Indiana University-Purdue University Indianapolis (IUPUI) / The purpose of this thesis is to use experimental methods to seek deeper understanding and better performance in the self-circulating self-regulating microfluidic gas generator initially developed in Dr. Zhu’s group, by changing the major features and dimensions in the reaction channel of the device. In order to effectively conduct experiments described above, a microfabrication method that is capable of making new microfluidic devices with low cost, short time period, as well as relatively high accuracy was needed first. Developing such a fabrication method is the major part of this thesis. We initially used patterned polymer films and glass slide, and bonded them together by sequentially aligning and stacking them into a microfluidic device with patterned double-sided tapes. Later we developed a more advanced microfabrication method that used only patterned polystyrene (PS) films. The patterned PS films were obtained from a digital cutter and they were bonded into a microfluidic device by thermopress bonding method that required no heterogeneous bonding agents. This new method did not need manual assembly which greatly improved its precision (~ 100 µm), and it used only PS as device material that has favorable surface wetting property for microfluidics applications. In order to find the optimized microfluidic channel design to improve gas generating performance, we've designed and fabricated microfluidic devices with different channel dimensions using the PS fabrication method. Based on the gas generation testing results of those devices, we were able to come up with the optimal dimensions for the reaction channel that had the best gas generation performance. To obtain a more fundamental understanding about the working mechanism of our device and its bubble dynamics, we have conducted ultrafast X-ray imaging test at Advanced Photon Source (APS), Argonne National Laboratory. High speed (100 KHz) phase contrast images were captured that allowed us to observe directly inside the reaction channel on the cross section view during the self-circulating catalytic reaction. The images provided us with lots of insightful information that in turn helped the dimensional improvement for the microchannel design. The 100 KHz high speed images also gave us useful information about the dynamics of bubble development on a catalyst bed, such as growth and merging of the bubbles.

<p>The use of silicon nanoneedles provides a unique and versatile biointerface for a range of biomedical applications. In this work, we propose a rational design for vertical Si nanoneedles that are printed on a polymer substrate for ocular drug delivery, intracellular recording, and intra-organoid sensing. To enable minimally invasive and long-term sustained delivery of ocular drugs, we integrate vertical Si nanoneedles with a tear-soluble contact lens for ocular drug delivery. We demonstrate the effectiveness of this platform in treating corneal neovascularization in an in vivo rabbit model, surpassing the current gold standard surgical therapy. This platform has the potential to revolutionize the management of various chronic ocular diseases without causing significant side effects.</p> <p>To enable intracellular recording, we present a unique platform consisting of vertical Si nanoneedles coated with a thin, transparent network of Au-Ag nanowires. This platform is held in place and enclosed by a soft, transparent elastomer, providing simultaneous intracellular recording and live imaging with applications in neuroscience, cardiology, muscle physiology, and drug screening. To demonstrate the utility of this platform, we monitored electrical potentials from cardiomyocyte cells and cardiovascular organoids. Additionally, we propose an intra-organoid sensing platform with vertical Si nanoneedles transfer printed into a soft scaffold. This platform can be adjusted and tailored for various organoids and tumor tissues of interest, or used to deliver bioactive molecules of interest into organoids in response to external stimuli.</p> <p>Our proposed designs of vertical Si nanoneedles based platforms demonstrate their significant potential for a broad range of biomedical applications, including ocular drug delivery, intracellular recording, and intraorganoid sensing. These platforms have the potential to revolutionize current approaches and pave the way for future developments in biomedical research and clinical applications, offering new possibilities for the diagnosis and treatment of a wide range of diseases.</p>

I takt med att tekniken för mikroelektromekaniska system utvecklas uppkommer det nya områden för tillämpning. Ett område är inom gassensorer där icke-dispersiv infraröd strålning används genom att mäta absorptionen hos olika gaser för att bestämma mängden av en specifik gas i luften. I detta projekt var målet att använda en vågledare med en infraröd lysdiod på ena sidan och en fotodetektor på andra sidan där vågledaren har som uppgift att utsätta ljuset för maximal mängd koldioxid innandet träffar fotodetektorn. Motiveringen för valet av koldioxid var att det är en gas som har stor påverkan på både klimat och arbetsmiljö. Metoden som ansågs vara bäst för placeringen av tidigare nämnda komponenter var att använda programmerbara rörelseenheter som kallas hexapod som består av sex ben som möjliggör tredimensionella rörelser och rotationer kring varje axel i det kartesiska koordinatsystemet. Experiment där elektromagnetiska störningar från lysdioden undersöktes vilket visade att det förekom elektromagnetisk störning samt att lysdioden påverkade fotodetektorn genom spridning trots att lysdiod och fotodetektor inte var vända mot varandra. / As the technology for microelectromechanical systems develops, new areas of application are emerging. One area is within gas sensors where non-dispersive infrared radiation is used by measuring the absorption of various gases to determine the concentration of a specific gas in the air. In this project, the goal was to use a waveguide with an infrared LED on one side and a photodetector on the other side where the waveguide has the task of exposing the light to the maximum amount of carbon dioxide before it hits the photodetector. The reason for the choice of carbon dioxide was that it is a gas that has a great impact on both the climate and the working environment. The method that was considered to be best for the placement of the aforementioned components was to use programmable motion units called hexapods which consist of six struts that enable three-dimensional movements and rotations around each axis of the Cartesian coordinate system. Experiments in which the electromagnetic interference from the LED were investigated showed that there was electromagnetic interference and that the LED affected the photodetector by scattering, even though the LED and photodetector were not facing each other.

The development of micro and nano-electromechanical systems (MEMS and NEMS) with entirely new or improved functionalities is typically based on novel or improved designs, materials and fabrication methods. However, today’s micro- and nano-fabrication is restrained by manufacturing paradigms that have been established by the integrated circuit (IC) industry over the past few decades. The exclusive use of IC manufacturing technologies leads to limited material choices, limited design flexibility and consequently to sub-optimal MEMS and NEMS devices. The work presented in this thesis breaks new ground with a multitude of novel approaches for the integration of non-standard materials that enable the fabrication of 3D micro and nanoelectromechanical systems. The objective of this thesis is to highlight methods that make use of non-standard materials with superior characteristics or methods that use standard materials and fabrication techniques in a novel context. The overall goal is to propose suitable and cost-efficient fabrication and integration methods, which can easily be made available to the industry. The first part of the thesis deals with the integration of bulk wire materials. A novel approach for the integration of at least partly ferromagnetic bulk wire materials has been implemented for the fabrication of high aspect ratio through silicon vias. Standard wire bonding technology, a very mature back-end technology, has been adapted for yet another through silicon via fabrication method and applications including liquid and vacuum packaging as well as microactuators based on shape memory alloy wires. As this thesis reveals, wire bonding, as a versatile and highly efficient technology, can be utilized for applications far beyond traditional interconnections in electronics packaging. The second part presents two approaches for the 3D heterogeneous integration based on layer transfer. Highly efficient monocrystalline silicon/ germanium is integrated on wafer-level for the fabrication of uncooled thermal image sensors and monolayer-graphene is integrated on chip-level for the use in diaphragm-based pressure sensors. The last part introduces a novel additive fabrication method for layer-bylayer printing of 3D silicon micro- and nano-structures. This method combines existing technologies, including focused ion beam implantation and chemical vapor deposition of silicon, in order to establish a high-resolution fabrication process that is related to popular 3D printing techniques. / <p>QC 20121207</p>