Energy poverty is the lack of access to the basic energy resources needed for human development. Fossil fuels, through their heavy emissions and transience, are slowly but surely leaving room for change in the energy sector as renewable energy sources rise to the challenge of sustainable, clean, and cost-efficient energy production. Because it is mostly located in rural areas, solutions crafted against energy poverty need to be appropriate for those areas and their development objectives. As top contenders, photovoltaics insertion in the energy market has largely soared creating, therefore, a need for its distributed energy resources to interconnect appropriately to the area electrical power system. EEE Senior Design Team 11 saw in this the need to design an advanced photovoltaic inverter with those desired grid functions but also leveraging the technological superiority of wide bandgap devices over silicon semiconductors. The honors creative project is an integral part of the senior design capstone project for Team 11. It has a two-front approach, first exploring the IEEE 1547-2018 standard on distributed energy resources; then focusing on the author’s personal contribution to the aforementioned senior design project: digital signal processing and grid support implementation. This report serves as an accompanying write up to the creative project.

The purpose of this research is to optically characterize germanium-based chalcogenide thin films and evaluate how their properties change when the composition is altered. The composition changes based on if the chalcogenide contains selenium or sulfur, if the film is 60 nanometers or 200 nanometers, and if the film is doped with silver (ranging from 0 nanometers to 30 nanometers). These amorphous germanium-chalcogenide thin films exhibit interesting properties when doped with silver, such as transporting ions within the film in addition to electron transport. Using optical characterization techniques such as UV-Vis spectroscopy, profilometry, and ellipsometry, parameters that describe the optical characteristics are found, including the absorption coefficient, refractive index, optical band gap energy, and information on the density of states. This research concludes that as silver content within the film increases, the optical bandgap energy decreases—this is a consistent trend in existing literature. Having a better understanding of the materials’ physical properties will be useful to aid in the creation of microsystems based on these materials by selecting optimal composition and growth conditions. Important applications using these materials are currently being researched, including variable capacitor devices relying on the ionic conductor behavior these materials display. The optical properties like the absorption coefficient and the optical bandgap energy are invaluable in designing these applications effectively.

In this project, an existing waveform generator designed by the vagus nerve stimulation (VNS) technology firm Hoolest Performance Technologies was modified and characterized. Voltage feedback and current feedback systems were designed in order to improve output voltage and current regulation. A wireless communication system was implemented onboard the newly designed waveform generator in order to improve user experience and allow the system to be controlled remotely. Finally, a custom printed circuit board was designed according to the established circuit schematics for the above components, and the layout was miniaturized to a total board footprint area of 1.5 square inches. The completed device was characterized according to several figures of merit including current consumption, voltage and current regulation, and short-circuit behavior.

Early detection and treatment of disease is paramount for improving human health and wellness. Micro-scale devices promote new opportunities for the rapid, cost-effective, and accurate identification of altered biological states indicative of disease early-onset; these devices function at a scale more sensitive to numerous biological processes. The application of Micro-Electro-Mechanical Systems (MEMS) in biomedical settings has recently emerged and flourished over course of the last two decades, requiring a deep understanding of material biocompatibility, biosensing sensitively/selectively, biological constraints for artificial tissue/organ replacement, and the regulations in place to ensure device safety. Capitalizing on the inherent physical differences between cancerous and healthy cells, our ultra-thin silicone membrane enables earlier identification of bladder cancer—with a 70% recurrence rate. Building on this breakthrough, we have devised an array to multiplex this sample-analysis in real-time as well as expanding beyond bladder cancer. The introduction of new materials—with novel properties—to augment current and create innovative medical implants requires the careful analysis of material impact on cellular toxicity, mutagenicity, reactivity, and stability. Finally, the achievement of replacing defective biological systems with implanted artificial equivalents that must function within the same biological constraints, have consistent reliability, and ultimately show the promise of improving human health as demonstrated by our hydrogel check valve. The ongoing proliferation, expanding prevalence, and persistent improvement in MEMS devices through greater sensitivity, specificity, and integration with biological processes will undoubtedly bolster medical science with novel MEMS-based diagnostics and therapeutics.

In this thesis, the methods of aluminum electroplating in an ionic liquid for silicon solar cell front side metallization were studied. It focused on replacing the current silver screen printing with an alternative metallization technology using a low-cost Earth-abundant metal for mass production, due to the high cost and limited availability of silver. A conventional aluminum electroplating method was employed for silicon solar cells fabrication on both p-type and n-type substrates. The highest efficiency of 17.9% was achieved in the n-type solar cell with a rear junction, which is comparable to that of the same structure cell with screen printed silver electrodes from industrial production lines. It also showed better spiking resistant performance than the common structure p-type solar cell. Further efforts were put on the development of a novel light-induced plating of aluminum technique. The aluminum was deposited directly on a silicon substrate without the assistance of a conductive seed layer, thus simplified and reduced the process cost. The plated aluminum has good adhesion to the silicon surface with the resistivity as low as 4×10–6 -cm. A new demo tool was designed and set up for the light-induced plating experiment, aiming to utilize this technique in large-size solar cells fabrication and mass production. Besides the metallization methods, a comprehensive sensitivity analysis for the efficiency dispersion in the production of crystalline-Si solar cells was presented based on numerical simulations. Temperature variation in the diffusion furnace was the most significant cause of the efficiency dispersion. It was concluded that a narrow efficiency range of ±0.5% absolute is achievable if the emitter diffusion temperature is confined to a 13˚C window, while other cell parameters vary within their normal windows. Possible methods to minimize temperature variation in emitter diffusion were proposed.

Breast microcalcifications are a potential indicator of cancerous tumors. Current visualization methods are either uncomfortable or impractical. Impedance measurement studies have been performed, but not in a clinical setting due to a low sensitivity and specificity. We are hoping to overcome this challenge with the development of a highly accurate impedance probe on a biopsy needle. With this technique, microcalcifications and the surrounding tissue could be differentiated in an efficient and comfortable manner than current techniques for biopsy procedures. We have developed and tested a functioning prototype for a biopsy needle using bioimpedance sensors to detect microcalcifications in the human body. In the final prototype a waveform generator sends a sin wave at a relatively low frequency(<1KHz) into the pre-amplifier, which both stabilizes and amplifies the signal. A modified howland bridge is then used to achieve a steady AC current through the electrodes. The voltage difference across the electrodes is then used to calculate the impedance being experienced between the electrodes. In our testing, the microcalcifications we are looking for have a noticeably higher impedance than the surrounding breast tissue, this spike in impedance is used to signal the presence of the calcifications, which are then sampled for examination by radiology.

In competitive Taekwondo, Electronic Body Protectors (EBPs) are used to register hits made by players during sparring. EBPs are comprised of three main components: chest guard, foot sock, and headgear. This equipment interacts with each other through the use of magnets, electric sensors, transmitters, and a receiver. The receiver is connected to a computer programmed with software to process signals from the transmitter and determine whether or not a competitor scored a point. The current design of EBPs, however, have numerous shortcomings, including sensing false positives, failing to register hits, costing too much, and relying on human judgment. This thesis will thoroughly delineate the operation of the current EBPs used and discuss research performed in order to eliminate these weaknesses.

This document introduces the need for the Rest Egg system and defines an accessible method of smartphone integration. Excessive noise can prevent recovering patients and special needs persons from resting correctly. The Rest Egg was designed for these people- people who are in critical need of quality rest but are often unable to eliminate stressors themselves. This system ensures their environment is calm by alerting caretakers' smartphones if noise reaches abrasive levels. Smartphones were the preferred device due to the wide spread of such devices in today's market. After making open sourcing a goal, something ubiquitous and affordable \u2014 yet usable and dependable \u2014 was necessary for the alert system. These requirements lead to the election an online alert service: Pushover, a trademark and product of Superblock, LLC.

With the progression of different industries moving away from employing secretaries for business professionals and professors, there exists a void in the area of personal assistance. This problem has existing solutions readily available to replace this service, i.e. secretary or personal assistant, tend to range from expensive and useful to inexpensive and not efficient. This leaves a low cost niche into the market of a virtual office assistant or manager to display messages and to help direct people in obtaining contact information. The development of a low cost solution revolves around the software needed to solve the various problems an accessible and user friendly Virtual Interface in which the owner of the Virtual Office Manager/Assistant can communicate to colleagues who are at standby outside of the owner's office and vice versa. This interface will be allowing the owner to describe the status pertaining to their absence or any other message sent to the interface. For example, the status of the owner's work commute can be described with a simple "Running Late" phrase or a message like "Busy come back in 10 minutes". In addition, any individual with an interest to these entries will have the opportunity to respond back because the device will provide contact information. When idle, the device will show supplemental information such as the owner's calendar and name. The scope of this will be the development and testing of solutions to achieve these goals.

Communication between the physical and digital world via software, embedded sensors and network connectivity is referred to by the term, the "Internet of Things" (IoT) [1]. The IoT transforms natural objects into "smart devices" to improve accuracy, reduce human intervention, and provide real-time data [1]. Smart weather stations that upload information, including temperature and humidity, to the Internet are already available. However, these products are often expensive and programmed only for single-purpose use. The LoRa Weather Station is a low cost, low power and low maintenance IoT solution that combines Microchip Technology's LoRa RN2903 module along with Mikroelektronika's Weather Click sensor. This report discusses how the LoRa Weather Station was created, primarily focusing on the LoRa gateway setup by a Raspberry Pi local web server. This project was completed by four electrical engineering students in the EEE 488 and 489 Senior Design courses at Arizona State University from Fall 2016 to Spring 2017. Total expenses for the project were $717.84, including the LoRa gateway which amounted to $104 (see Appendix C for the Bill of Materials).