2009 PARASCA SCIENCE RESEARCH AWARD ABSTRACTS
Cheyenne Alabanzas (BS, Engineering): "The Microstructural and Biomechanical Property Differences of Spinal Rods from Different Lots."
Faculty Mentor: Anthony Paris, Engineering
Abstract: The objective of this project is to obtain a qualitative and quantitative comparison of the static biomechanical behavior of stainless steel and titanium spinal rods from different lots. Static testing will be done in a controlled environment, which will then provide data for analysis and conclusion.
The spinal rod is a surgical device used to correct deformities of the spine due to medical conditions such as scoliosis and degenerative disc disease. Commonly, rods are implanted along the spinal column to support the fusion of the vertebrae. The spine is fixed when the grafted bone fuses into a solid bone mass, immobilizing the vertebrae. Since this takes up to a year to develop, the instrumentation aids in allowing the fusion to occur by making the spine stiff. When the fusion is solid, the instrumentation can be removed, although it is usually left in place. The instrumentation may eventually fatigue and fail if fusion is not achieved. Rigid internal fixation is required to enhance fusion rates and ensure mechanical stability.
Spinal rods are mass produced in lots. It was observed during a previous study by the Faculty Advisor that the behavior of the rods during cutting, bending, and testing varied significantly from one lot number to another. It was concluded that although rods are produced to meet the established ASTM standards, there are significant variations in the biomechanical properties of the rods from different lots.
Due to variations in the manufacturing process – including small variations in chemical composition and variations in heat treatment, cold work, and surface treatment from one lot number to another – there will be variations in the microstructure of the rods. Variations in microstructure result in variations in the biomechanical properties. This project will examine those differences in biomechanical properties and microstructure both qualitatively and quantitatively and discuss their effects on clinical performance.
Samples of the spinal rods will be obtained and subjected to biomechanical and microstructural testing. Each of the rods from different batches will be tested for their yield strength, tensile strength, ductility, metallography and hardness. Tensile tests will be performed using an MTS Universal Test Machine. Metallographic equipment will be used to determine the microstructure of the rods. Hardness tests will be performed using a Rockwell Hardness Tester.
The goal of this study is to determine the difference in microstructural and biomechanical properties of the titanium and stainless steel rods from different lots used for spinal instrumentation. A better understanding of the biomechanical behavior of spinal rods is important to physicians and patients considering rod implants, as well as to the engineers and scientists who are researching and designing spinal rod systems. To better understand spinal instrumentation from the clinical perspective, orthopedic surgeon Dr. Andres Munk, M.D., Macomb Orthopedic Surgeons, will serve as a collaborating researcher.
The results of the study will be published in a formal report and submitted for dissemination through conference and journal publications.
2008 PARASCA SCIENCE RESEARCH AWARD ABSTRACTS
Raphael Wunderle (BS Engineering): "Constant-Force Compliant Gripper Mechanism"
Faculty Mentor: Nicolae Lobontiu, Engineering
Abstract: The project proposes to model, design and experimentally test several constant-force compliant mechanism grippers that can be used for percision robotic manipulation. Compliant mechanisms use flexure hinges (which are slender, flexible portions that can bend and enable relative rotation between rigid links) instead of classsical translation and rotation joints. These devices are very modern and significant research efforts are currently dedicated to flexure-based compliant mechanisms, particularly with applications to micro/nano electromechanical systems (MEMS/NEMS) and precision positioning devices. The goal of this project is to design compliant grippers by amplifying an input motion from a linear actuator and to create a constant ourput force, which would enable grasping of objects having various dimensions through application of the same gripping force. Both amplification and constant force output will be created through design by selecting the proper geometric configuration. A constant force output for different displacements will be achieved by the change of the length and therefore the stiffness of the gripper arms. Various gripper designs will be studied and modeled with Solid Works or AUTO Cad and then analyzed with the finite element analysis software ANSYS. After finding the optimal geometry for an adequate amplification and, more importantly, for a constant force output, a planar compliant gripper will be fabricated. Furthermore, a force sensor will be modeled, designed and fabricated to perform force tests with the gripper prototype. This sensor will also be based on compliant mechanism. Both the gripper and the force sensor designs will be sent at drawing files to the company which will fabricate these mechanisms by electric discharge machining (EDM). The fabricated gripper will then be tested in the School of Engineering's labs at UAA by using the compliant force sensor as well as other sensors which are already available in the Engineering labs or the sensors which will be aquired through this project.
2007 PARASCA SCIENCE RESEARCH AWARD ABSTRACTS
Athea Alabanzas (BS Engineering major): "The treatment of Alaska water using Titanium Dioxide Photocatalyst"
Faculty Mentor: Nyree McDonald
Abstract: The potential harmful environmental implications of pharmaceuticals and personal care products (PPCP's) continue to worry scientists. Although the specific effects of these compounds are not entirely identified, water treatment processes have to be employed to ensure water quality. Removal of PPCP's from wastewater of drinking water requires advanced oxidation processes, such as ozonation and activated titanium dioxide (TiO2). This proposal investigates the impact UV activated TiO2may have on the degradation of common PPCP's like caffeine and aspirin. In addition, the treatise examines the degradation of natural organic matter by UV activated TiO2. The TiO2 catalyst will be added to the water and exposed to UV activation with samples of the water taken periodically and tested to determine a variety of water quality parameters including total organic carbon and color. All tests are performed in accordance with the Standards Methods for the Examination of Water and Wastewater 21st Edition manual. This project seeks to determine the effectiveness of titanium dioxide photocatalysis in the treatment of Alaska waters.
