• 3-D printed heterogenous substrate bandpass filters

      Nesheiwat, Issa (2021-09)
      With the demand for increasing frequencies in today’s communications systems, compact integrated circuits are challenging to achieve. Compact filters have typically been realized by modifying the circuit design including using LC resonators, defective ground structures, and adjusting the length ratios of resonators. Heterogenous substrates with controlled regions of dielectric loading offer a new design approach when it comes to manufacturing an RF component. In this thesis, additive manufacturing is used to selectively place low-K and high-K dielectric materials to achieve a compact form factor, improved bandwidth, and higher suppression in re-entry modes. First, microstrip coupled strip lines are simulated to model the basic coupling effects of loading a substrate. Next, three 2.45GHz parallel coupled bandpass microstrip filters are designed with differing substrates: low-K, high-K and high-K loaded to analyze the impact of loading within the substrate. The filter substrates are manufactured using a dual-extrusion FDM 3-D printer to combine both dielectrics, low-K ABS, and high-K PrePerm ABS1000, into a single heterogeneous substrate. Compared to the low-K dielectric alternative, the high-K loaded filter demonstrated a 30.8% decrease in length, while maintaining similar bandwidth and suppression of re-entry modes. Compared to the high-K filter, the high-K loaded filter showed a 9.4dB reduction in re-entry mode suppression, while maintaining similar footprint size.
    • Analysis of ground plane size, topography and location on a monopole antenna's performance utilizing 3-D printing

      Ciraco, Vito (2021-09)
      The monopole antenna is widely used in communication applications and is typically mounted on various surfaces that act as ground planes; a prime example being the roof of a car. The shape of the ground plane can drastically change the patterns of the electromagnetic radiation of a monopole antenna as well as its RF performance. Extensive work [1,12-13] has been done on the numerical modeling of arbitrarily shaped ground planes. However, due to their geometric complexity, there is very little work reported on the practical testing component of physical antennas with these obscure ground plane structures. This thesis illustrates how the additive manufacturing process presented can be used to physically realize arbitrarily shaped ground planes and provides a low-cost process to verify the numerical model. Ground Planes were modified while maintaining the same antenna length to evaluate the impact on antenna performance. The antenna was not optimized or changed to a standard antenna design. Varying radius spherical ground planes are modelled, as well as modified ground plane structures to evaluate the impact of the ground plane on a 1.3GHz monopole antenna's performance and in some cases to modify the antenna's performance in terms of gain, bandwidth, and radiation pattern. Designs such as the planar ground with horn was found to enhance monopole bandwidth by more than 5 times that of a standard planar ground but significantly deteriorate the antenna's radiation pattern. Moreover, complex geometry such as the fin sphere ground plane offered a 25% increase in gain relative to the standard sphere ground. Designs like the edge-mounted sphere can offer directive gain and radiation characteristics simply by altering the antennas' location mount location with respect to its ground plane. The techniques presented in this thesis offer new ways of producing 3-D printed ground planes for RF applications that are easier to manufacture, lighter in weight, and can enhance antenna performance over their conventional counterparts.
    • Diplopia: MFA Thesis - Metals

      Grabher, Lena Christina (2015-05)
      Visible and mobile, my body is a thing among things; it is one of them. It is caught in the fabric of the world, and its cohesion is that of a thing. But because it sees and moves itself, it holds things in a circle around itself. (― Maurice Merleau-Ponty) Diplopia refers to the symptom of seeing two images instead of one. In my work, I manipulate aspects of physical appearance. Using the language of jewelry, I explore optics and illusion. Jewelry as a traditional means of adornment is a part of our appearance, and therefore a medium to explore personal identity. Jewelry and our skin - both can be seen as a layer that shape our appearance. I use jewelry to create a symbiotic relationship between the body and its environment, using light projection or mirroring to manipulate the boundary between the two. As Damian Skinner asserts in his book Contemporary Jewelry in Perspective, “The space of the body, and its variability and particularity as a space to show an object, complicates perception, and simultaneously activates the object in a transformative way.” Therefore my goal is to create jewelry that not only stands alone as an object but obtains its function when worn.
    • Meandering progression: MFA Thesis - Drawing & Painting

      Loveszy, Rosa (2019-05)
      Observation of interior organic forms and microscopic environments inspired my interest the correlation between macro and microstructures in the universe. The flow of movement and material in natural settings, whether large or small, develop similar patterns over time. How can we identify regularities caused by liquid moving through matter? Using a methodology inspired by organic shapes and systems of growth, the intrinsic properties of encaustic medium and steel allow for the paint and construction to reflect patterns of natural progress. Patterns found in nature that are visible in everyday life informs my intellectual and creative process. I consistently look for ways to make complex structures out of simple building blocks. This search has led me to peer through a microscope and observe the small shapes that coalesce to construct the world as we know it. An integral part of my studio practice is not only the physical creation of art, or its formal properties, but the intellectual stimulation that comes from broadening my understanding of the universe. Consistently I am overwhelmed by the breadth of the knowledge and information available to aid our understanding of life. Through my research on growth patterns in the natural world, I have discovered exciting visuals that recently have been captured by modern scientific instruments. Looking through a microscope, I have been intrigued by the ability of a lens to reveal environments invisible to the naked eye. Depending on the lens we can observe a vast landscape of the growth patterns.
    • Passively powered pH sensor for study of gastric disorders

      Piaquadio, Nicholas; Hart, Kevin; Hart, Sean; Lundgren, Tucker (2019-05)
      A fully passive wireless implantable pH sensor that is implantable in an animate silicone stomach environment has been developed for the study of gastric disorders. The system has applications in medical training and testing. It can be used for pH monitoring as well as testing the efficiency of antacid medication. To achieve this, wireless power is sent from a reading circuit, via a class E amplifier connected to an inductive coil. The implanted circuit harvests the energy sent with a charge pump, and returns the measured pH via Frequency Shift Keying (FSK) modulation. The electronic components were simulated using Keysight Advanced Design System (ADS), prototyped on breadboards, amended, and finally manufactured onto Printed Circuit Boards (PCBs). To make the stomach, an injection molding process was employed using a sacrificial wax inner core and a 3D printed mold. The completed stomach model features 5mm thick walls at life-size scale, and demonstrates realistic digestive motion. The current implant design uses a traditional pH probe for proof of concept, fits within the stomach at 2.5cm by 5cm, and is capable of returning readings at a distance of up to 4 inches with an accuracy within 0.2pH. The reader coil can read pH once every ten minutes for 43 hours on a single charge.
    • That Which Is There: MFA Thesis - Drawing and Painting

      Privitera, Olivia (2016-05)
      Light exposes the contradiction between materiality and invisibility. I explore the impression of nuanced spaces and notions of illusion to suspend optical perceptions of spatial temporality. Using light to alter visual experience, regardless of how physical objects structure boundaries, I illuminate our consciousness of these subtle shifts and how they transform perception and thought. Light, shadow, reflections, and shifting impressions are tools that I use to generate a new sensation of space and time constructs — between the physical nature of the external world as we perceive it and our cognitive processes. I research and experiment with perception, specifically within the philosophical framework of Phenomenology. Evidence of other dimensions is readily available, though not fully integrated into our consciousness that visualizes and responds to the corporeal world and the visible spectrum of light. The dynamic shifts that alter our cognitive perception remain the overall impulse for my projects. Manipulating light and shadows through original 3D printed structures, a variety of glass lenses, and constructive elements such as wood, I frame immaterial phenomena and encourage the sensation of illusory dimensions.
    • Water: MFA Thesis - Ceramics

      Heitmeyer, Sarah (2016-12)
      This MFA Thesis exhibits research regarding a sublime experience when encountering a moment of beauty, through the medium of digitally designed and hand crafted tile. "I return to the water’s edge to feel my mind empty before me. Water gives form to a swell of intentions, released to drift, reflect, and find resonance with the tide. I pair digital and craft based techniques to infiltrate contemporary design and honor traditions of handmade ceramics. Patterns function as a vehicle through space, offering markers for perception and revealing a subliminal tendency to seek order and repetition. Creating patterns with Computer Aided Design, mold making and slip casting, allow me to offer an experience that provides the viewer with a quiet, immense moment."
    • Windows of (dis)connection: MFA Thesis - Ceramics

      An, Jiyu (2021-05)
      In my work, I am using the images of the city and windows. Viewers can read the reflected images of fragility and disconnection in my work. The window is a sign of human emotions. How can I make the viewer feel that we are disconnected and fragile? I think the windows and cities can be signifiers and mirror all emotions.