The LightCube mission is a CubeSat whose goal is to allow users to manually flash a light that is observable by the naked eye. LightCube required the design of custom electronics because of its small size and unique mission. The majority of the volume of LightCube was taken up by the payload electronics, precluding any use of most off the shelf CubeSat components. A custom EPS system was designed and developed by students at ASU to meet all the power requirements of LightCube. The satellite’s solar panels were constrained to a 1U size and the batteries were given a limited volume. The EPS was architected with these constraints in mind to optimize for the space given. It consists of a charging circuit, two converters, voltage and current measuring circuits, and a separate battery board which includes a battery fuel gauge, current sensor, inhibit circuitry, temperature sensor, heater, and optional linear battery charger. One of the underlying goals of this design was to make the EPS and battery board as simple as possible. The design was intentionally simple and left out other features such as a microcontroller for ease and speed of development as well as minimize complexity to lower the risk of catastrophic failure due to radiation or other space events.

Since the invention of the automobile, engineers have been designing and making newer and newer improvements to them in order to provide customers with safer, faster, more reliable, and more comfortable vehicles. With each new generation, new technology can be seen being introduced into mainstream products, one of which that is currently being pushed is that of autonomy. Established brand manufacturers and small research teams have been dedicated for years to find a way to make the automobile autonomous with none of them being able to confidently answer that they have found a solution. Among the engineering community there are two schools of thought when solving this issue: camera and LiDAR; some believe that only cameras and computer vision are required while other believe that LiDAR is the solution. The most optimal case is to use both cameras and LiDAR’s together in order to increase reliability and ensure data confidence. Designers are reluctant to use LiDAR systems due to their massive weight, cost, and complexity; with too many moving components, these systems are very bulky and have multiple costly, moving parts that eventually need replacement due to their constant motion. The solution to this problem is to develop a solid-state LiDAR system which would solve all those issues previously stated and this research takes it one level further and looks into a potential prototype for a solid-state camera and Lidar package. Currently no manufacturer offers a system that contains a solid-state LiDAR system and a solid-state camera with computing capabilities, all manufacturers provided either just the camera, just the Lidar, or just the computation ability. This design will also use of the shelf COTS parts in order to increase reproducibility for open-source development and to reduce total manufacturing cost. While keeping costs low, this design is also able to keep its specs and performance on par with that of a well-used commercial product, the Velodyne VL50.

Nanoelectronics are electronic components that are often only a few nanometers in size. The field of nanoelectronics encompasses a wide range of products and materials that share the trait of being so small that physical forces can modify their characteristics on a nanoscale. These nanoscale devices are dominated by quantum processes including atomistic disorder and tunneling.In contrast to nanoelectronics, which involves the scaling down of devices to nanoscale levels, molecular electronics is concerned with electronic activities that take place within molecule structures. Detection of molecular conductance plays a vital role in the field of molecular electronics and nanotechnology. The ability to measure the conductive behavior of molecules is necessary to study their surface properties, defects, electronic structures, and for bio-sensing. To determine the conductance of the molecule, it is necessary to deduce the current passing through it. This is achieved by applying a voltage bias across the molecule and the detection instrument. Instruments like Scanning Tunneling Microscope (STM) and chip-based characterization (Probe Station) are used to fetch the amount of current flowing through the molecules. The current through molecules can be very small to measure and needs to be amplified. Linear amplifiers are widely used for amplifying these small currents, but due to their low dynamic range they are being replaced by logarithmic amplifiers. This thesis project aims to customize a logarithmic amplifier design to the interface with these instruments to measure the current flowing through these molecules. This thesis starts with a review of a linear- current amplifier-based technology that is used for measuring small currents and its challenges. It then introduces logarithmic amplifier for overcoming those obstacles. This thesis involves design, fabrication, and characterization of the built logarithmic amplifier. Furthermore, the setup includes a custom designed logarithmic amplifier that can be used with instruments like Scanning Tunneling Microscope (STM) and probe station. The key objective of the research is to accurately calibrate the logarithmic amplifier for measurement of currents over a wide range from picoamperes to milliamperes. Dummy resistors with different resistance values are used to replace the sample of which the conductance is to be measured, for testing and calibrating purposes. Bandwidth of the circuit is tested using these different values of resistors.

Highly reflective back surfaces are critical for reaching the detailed balance efficiency limits of photovoltaics. In addition to being highly reflective, the back surface and contact of the cell must have low resistance. A traditional approach to balance reflectance and contact resistance has been to use point contact geometries, which are process intensive. This work considers using a transparent conductive oxide and metal mirror, which, due to being two planar layers, can be fabricated much more easily. To study the tradeoff between resistance and absorptance for this contact, the oxide doping concentration is varied. Test structures to measure the doping concentration, contact resistance, and parasitic absorptance were fabricated. Using measured parameters, the performance of high-quality GaAs photonic power converters is modeled. Measurements show that although the contact resistance is comparatively high, it can be controlled through doping in the oxide and semiconductor composition. Furthermore, modeling shows the contact resistance is not prohibitively high for one-sun or lower illumination level devices. The hemispheric reflectance of the experimental oxide/metal back contact is modeled to be 96.7%, which is quite high considering that it is a conductive back contact. Although the oxide/metal contact structure does not perform electrically or optically as well as more complex point contact structures, this work indicates the advantages of the planar transparent conductive oxide/metal contact structure near one-sun equivalent current densities for solar cells and photonic power converters, where it is desirable to avoid the device fabrication costs of back contact patterning.

Neurological disorders are the leading cause of physical and cognitive declineglobally and affect nearly 15% of the current worldwide population. These disorders include, but are not limited to, epilepsy, Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. With the aging population, an increase in the prevalence of neurodegenerative disorders is expected. Electrophysiological monitoring of neural signals has been the gold standard for clinicians in diagnosing and treating neurological disorders. However, advances in detection and stimulation techniques have paved the way for relevant information not seen by standard procedures to be captured and used in patient treatment. Amongst these advances have been improved analysis of higher frequency activity and the increased concentration of alternative biomarkers, specifically pH change, during states of increased neural activity. The design and fabrication of devices with the ability to reliably interface with the brain on multiple scales and modalities has been a significant challenge. This dissertation introduces a novel, concentric, multi-scale micro-ECoG array for neural applications specifically designed for seizure detection in epileptic patients. This work investigates simultaneous detection and recording of adjacent neural tissue using electrodes of different sizes during neural events. Signal fidelity from electrodes of different sizes during in vivo experimentation are explored and analyzed to highlight the advantages and disadvantages of using varying electrode sizes. Furthermore, the novel multi-scale array was modified to perform multi-analyte detection experiments of pH change and electrophysiological activity on the cortical surface during epileptic events. This device highlights the ability to accurately monitor relevant information from multiple electrode sizes and concurrently monitor multiple biomarkers during clinical periods in one procedure that typically requires multiple surgeries.

With the demand growing for more sustainable forms of energy in replacement of fossil fuels, a major obstacle arises in the end-of life solar modules that are disposed of in landfills. Aside from the hazardous materials, silicon solar modules contain valuable and scarce materials such as silver. Silver is used in many industries and many applications therefore the recycling and recovering of it is financially beneficial. The purpose of this research was to achieve high purity and recovery of silver using hydrofluoric acid. The following work presents the feasibility of silver recovery through the process of leaching and electrowinning by examining the percent recovery and cathodic coulombic efficiency, followed by a chemical analysis to determine the purity. Varying conditions in leaching and electrowinning parameters are conducted in a synthetic solution to determine the effect on silver recovery and cathodic coulombic efficiency. It was determined that the silver recovery was dependent on the applied potential, system configuration and time. The system is capable of recovery rates of over 95% at -1 V. The system is further tested on solar cells to prove that silver can be recovered. There was over 99% purity from the experiments conducted in synthetic solution and from solar cells. Additionally, a circular chemistry is proposed that allows the reuse of hydrofluoric acid for leaching and electrowinning.

The silicon-based solar cell has been extensively deployed in photovoltaic industry and plays an important role in renewable energy industries. A more energy-efficient, environment-harmless and eco-friendly silicon production technique is required for price-competitive solar energy harvesting. Silicon electrorefining in molten salt is promising for the ultrapure solar-grade Si production. To avoid using highly corrosive fluoride salt, CaCl2-based salt is widely employed for silicon electroreduction. For Si electroreduction in CaCl2-based salt, CaO is usually added to enhance the solubility of SiO2. However, the existence of oxygen in molten salt could result in system corrosion, anode passivation and the co-deposition of secondary phases such as CaSiO3 and SiO2 at the cathode. This research focuses on the development of reusable oxygen-free CaCl2-based molten salt for solar-grade silicon electrorefining. A new multi-potential electropurification process has been proposed and proven to be more effective in impurities removal. The as-received salt and the salt after electrorefining have been electropurified. The inductively-coupled plasma mass spectrometry and cyclic voltammetry have been utilized to determine the impurities removal of electropurification. The salt after silicon electrorefining has been regenerated to its original purity level before by the multi-potential electropurification process, demonstrating the feasibility of a reusable salt by electropurification. In an oxygen-free CaCl2-based salt without silicon precursor, the silicon dissolved from the silicon anode can be successfully deposited at the cathode. The silicon anode has been operated for more than 50 hours without passivation in the oxygen-free system. Silicon ions start to be deposited after 0.17 g of silicon has been dissolved into the salt from the silicon anode. A 180 µm deposit with a silver-luster surface was obtained at the cathode. The main impurities in the silicon anode such as aluminum, iron and titanium were not found in the silicon deposits. No oxygen-containing secondary phases are detected in the silicon deposits. These results confirm the feasibility of silicon electrorefining in the oxygen-free CaCl2-based salt.

Dynamical decoupling (DD) is a promising approach to mitigate the detrimental effects that interactions with the environment have on a quantum system. In DD, the finite-dimensional system is rotated about specified axes using strong and fast controls that eliminate system-environment interactions and protect the system fromdecoherence. In this thesis, the framework of DD is theoretically studied, and later it discusses how this framework can be implemented on an infinite-dimensional system that amplifies system components rather than suppressing them through quadrature squeezing operations. It begins by studying the impact of system-environment interactions on a quantum system, and then it analyzes how DD suppresses these interactions. The conditions for protecting a finite-dimensional system through DD are reviewed, and a numerical analysis of the DD conditions for simple systems is conducted. Using bang-bang controls, a framework for decoupling decoherence-inducing components from a general finite-dimensional system is studied. Later, following an overview of schemes that amplify the strength of a quantum signal through reversible squeezing, a theoretical study of Hamiltonian Amplification (HA) for quantum harmonic oscillators is presented. By implementing the DD framework with squeezing operations, HA achieves speed-up in the dynamics of quantum harmonic oscillators, which translates into the strengthening of interactions between harmonic oscillators. Finally, the application of HA in amplifying the third-order nonlinearity in a Kerr medium is proposed to obtain a speed-up in the implementation of controlled phase gates for optical quantum computations. Numerically simulated results show that large amplification in nonlinearity is feasible with sufficient squeezing resources, completing the set of universal quantum gates in optical quantum computing.

The strong demand for the advancing of Moore’s law on device size scaling down has accelerated the miniaturization of passive devices. Among these important electronic components, inductors are facing challenges because the inductance value, which is strongly dependent on the coil number for the air core inductor case, will be sacrificed when the size is shrinking. Adding magnetic core is one of the solutions due to its enhancement of inductance density but it will also add complexity to the fabrication process, and the core loss induced by the eddy current at high frequency is another drawback. In this report, the output of this research will be presented, which has three parts. In the first part, the CoZrTaB thin films are sputtered on different substrates and characterized comprehensively. The laminated CoZrTaB thin films have been also investigated, showing low coercivity and anisotropy field on both Si and polyimide substrates. Also, the different process conditions that could affect the magnetic properties are investigated. In the second part, Ansys Maxwell software is used to optimize the lamination profile and the magnetic core inductor structure. The measured M-H loop is imported to improve the simulation accuracy. In the third part, a novel method to fabricate the magnetic core inductors on flexible substrates is proposed. The sandwich magnetic core inductor is fabricated and assembled with flipchip bonder. The measurement result shows that this single-turn magnetic core inductor can achieve up to 24% inductance enhancement and quality factor of 7.42. The super low DC resistance (< 60 mΩ) proves that it is a good candidate to act as the passive component in the power delivery module and the use of polyimide-based substrate extends its compatibility to more packaging form factors.

The development of biosensing platforms not only has an immediate lifesaving effect but also has a significant socio-economic impact. In this dissertation, three very important biomarkers with immense importance were chosen for further investigation, reducing the technological gap and improving their sensing platform.Firstly, gold nanoparticles (AuNP) aggregation and sedimentation-based assays were developed for the sensitive, specific, and rapid detection of Ebola virus secreted glycoprotein (sGP)and severe acute respiratory syndrome coronavirus 2 (SARS-COV2) receptor-binding domain (RBD) antigens. An extensive study was done to develop a complete assay workflow from critical nanobody generation to optimization of AuNP size for rapid detection. A rapid portable electronic reader costing (<$5, <100 cm3), and digital data output was developed. Together with the developed workflow, this portable electronic reader showed a high sensitivity (limit of detection of ~10 pg/mL, or 0.13 pM for sGP and ~40 pg/mL, or ~1.3 pM for RBD in diluted human serum), a high specificity, a large dynamic range (~7 logs), and accelerated readout within minutes. Secondly, A general framework was established for small molecule detection using plasmonic metal nanoparticles through wide-ranging investigation and optimization of assay parameters with demonstrated detection of Cannabidiol (CBD). An unfiltered assay suitable for personalized dosage monitoring was developed and demonstrated. A portable electronic reader demonstrated optoelectronic detection of CBD with a limit of detection (LOD) of <100 pM in urine and saliva, a large dynamic range (5 logs), and a high specificity that differentiates closely related Tetrahydrocannabinol (THC). Finally, with careful biomolecular design and expansion of the portable reader to a dual-wavelength detector the classification of antibodies based on their affinity to SARS-COV2 RBD and their ability to neutralize the RBD from binding to the human Angiotensin-Converting Enzyme 2 (ACE2) was demonstrated with the capability to detect antibody concentration as low as 1 pM and observed neutralization starting as low as 10 pM with different viral load and variant. This portable, low-cost, and versatile readout system holds great promise for rapid, digital, and portable data collection in the field of biosensing.