Exploration of icy moons in the search for extra-terrestrial life is becoming a major focus in the NASA community. As such, the Exobiology Extant Life Surveyor (EELS) robot has been proposed to survey Saturn's Moon, Enceladus. EELS is a snake-like robot that will use helically grousered wheels to propel itself forward through the complex terrains of Enceladus. This moon's surface is composed of a mixture of snow and ice. Mobility research in these types of terrains is still under-explored, but must be done for the EELS robot to function. As such, this thesis will focus on the methodologies required to effectively simulate wheel interaction with cohesive media from a computational perspective. Three simulation tools will be briefly discussed: COMSOL Multiphysics, EDEM-ADAMS, and projectChrono. Next, the contact models used in projectChrono will be discussed and the methodology used to implement a custom Johnson Kendall Roberts (JKR) collision model will be explained. Finally, initial results from a cone penetrometer test in projectChrono will be shown. Qualitatively, the final simulations look correct, and further work is being done to quantitatively validate them as well as simulate more complex screw geometries.
Medical technology, while improving greatly with time, often requires a sacrifice in the form of invasiveness in order to reach target areas within the body, such as the brain, liver, or heart. This project aims to utilize a magnetic, flexible needle design to reach these target areas for surgery and drug administration with minimal invasiveness. The metallic needle tip is guided by an external system consisting of a UR16e robotic arm with a magnetic end effector. As a longer running project, the primary focuses of this research are to develop the system by which the robotic arm guides the needle, investigate and implement fiber Bragg grating sensors as a means of real time path imaging and feedback, and conduct preliminary tests to validate that the needle is accurately controlled by the robotic arm. Testing with different mediums such as gel or phantom tissue, and eventually animal experiments will follow in a future publication due to time constraints.
STEM programs are the programs for the future. Technology is advancing at a rapid speed and the world is trying to keep up. Engineering is leading the charge within that because engineers are always at the forefront of innovation. However, just the prospect of growth is not enough for students to want to become professional engineers. Black female students have the desire to better their knowledge by going to institutions of higher education, but they do not share that same passion for engineering education. This study aims to understand that. This research is looking into retention factors for students in engineering and how those factors can be transferred to Black women. It was found that factors like bias training for students and faculty, integration to engineering organizations, getting more Black female professors and faculty, and introduction to prerequisite courses like calculus and physics to Black females in grade school.
This project compared two optimization-based formulations for solving multi-robot task allocation problems with tether constraints. The first approach, or the ”Iterative Method,” used the common multiple traveling salesman (mTSP) formulation and implemented an algorithm over the formulation to filter out solutions that failed to satisfy the tether constraint. The second approach, named the ”Timing Formulation,” involved constructing a new formulation specifically designed account for robot timings, including the tether constraint in the formulation itself. The approaches were tested against each other in 10-city simulations and the results were compared. The Iterative Method could provide answers in 1- and 2-norm variations quickly, but its mTSP model formulation broke down and became infeasible at low city numbers. The 1-norm Timing Formulation quickly and reliably produced solutions but faced high computation times in its 2-norm manifestation. Ultimately, while the Timing Formulation is a more optimal method for solving tether-constrained task allocation problems, its reliance on the 1-norm for low computation times causes it to sacrifice some realism.
The goal of themed entertainment is to use activities and environments to tell a story and immerse the guest in a novel experience. By applying these concepts to nonfiction and educational topics, the concept of edutainment is created. In recent years museums have begun utilizing the concept of edutainment and techniques typically found in themed entertainment experiences to capture the attention and focus of guests and create experiences that connect emotionally with them. My goal in this thesis pathway project was to investigate this trend and technique of connecting with an audience and apply it to the STEAMtank project within ASU’s Innovation Space. The goal of STEAMtank is to design and fabricate children’s STEAM museum exhibits in two semesters with focus on accessible design. My team conducted research and interviews exploring current market trends in theme parks and museums, best practice designs and operations, and interests of children to develop the concept for our exhibit, Gust of Dust, which was then fine-tuned, constructed, and installed in the STEAMtank Exhibit Space. Gust of Dust is an exciting exhibit demonstrating the power of a haboob that was developed from preconcept to installation in under a year by two determined and talented interdisciplinary teams. Learning about haboobs connect concepts of environmentalism, earth science, and safety to real concepts in children’s lives.
An interface reconstruction algorithm for the Volume of Fluid (VOF) method is required for two-phase flow problems for advection of phase interface. The primary method for interface reconstruction has been through piecewise linear interface calculation (PLIC) reconstruction. However, while PLIC reconstruction is highly accurate at representing small curvature interfaces by approximating planes across multiple grid cells, accuracy problems arise when the size of the mesh is too coarse to accurately approximate a large curvature without resorting to refining the mesh. An elliptic interface reconstructing algorithm is explored for two-phase flow problems in 2D to determine the viability of a higher-order interface reconstruction algorithm. This requires first developing an area overlap function between an arbitrary triangle and ellipse, which is then extended to calculate the area fraction field of an ellipse within a mesh. Then, the "reverse" problem of elliptic interface reconstruction given an area fraction field is examined. A study is conducted to determine the presence of any local minimums when varying the ellipse parameters. In the future, a multi-dimensional root-finding solver using Newton's Method will be developed to properly reconstruct the elliptic interface given the area fraction field.
Experimental Characterization of Multifunctional Shape Memory Polymers With Carbon-Based Nanofillers
This paper focuses on the fabrication and characterization of shape memory polymer (SMP) with interspersed carbon-based nanofillers which showed significant improvements in quasi-static and dynamic mechanical properties. These composite shape memory polymers have been fabricated using a specialized acetone solvent mixing technique to achieve high dispersion. The effect of individual and hybrid additions of graphene oxide (GO) and carbon nanotubes (CNT) with a total nanofiller content of 2 wt.% was investigated. These high dispersion SMPs showed significant improvements in tensile moduli (up to 25% over baseline), tensile strength (up to 15% over baseline), and strain to failure (up to 75% over baseline), owing to crack propagation hindrance induced by the carbon nanofillers. Further, dynamic mechanical analysis (DMA) showed a minimal reduction in polymer chain mobility and improvements in storage modulus. Dispersion is characterized by micrograph acquisition and subsequent binary image processing.