The intent of this thesis it to find a correlation between the stiffness of granular jammed particles and the pressure of the vacuum initiating the jamming force. Currently, granular jamming is being used to create palpation simulators for physicians to practice feeling the variety of stiffnesses of organs when healthy or ill. Because granular jamming allows for variable stiffness of any shape, it is an apt phenomenon to simulate the change of rigidity organs like the liver undergoes when diseased. For physicians to correctly identify how stiff the organ must be when using these palpation simulators, there needs to be a way to know how much pressure must be applied to correctly simulate the stiffness of the organ for each specific scenario. This thesis will discuss how pressure affects stiffness by using the three-point bending test. To perform this test, a tubular balloon filled with coffee granules was used to represent the beam. An impact force as well as a hanging force was used to displace the beam. The displacement of the beam is adequate to find the Young's Modulus or stiffness of the beam of granules at different pressures provided by the vacuum. It was found that there is a correlation between stiffness and pressure of a granular jammed system. This will allow for future physicians to accurately and consistently use model organs to practice palpation techniques.
Bachelor of Science (B.S.)
College of Engineering and Computer Science
Mechanical and Aerospace Engineering
Quach, Christopher H., "Granular Jamming: Stiffness vs Pressure and Organ Palpation Devices" (2023). Honors Undergraduate Theses. 1407.