Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- Creators: School of Life Sciences
ContributorsNguyen, Sophie (Author) / Marvi, Hamidreza (Thesis director) / Ceylan, Hakan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Chemical Engineering Program (Contributor)
Created2023-12
ContributorsNguyen, Sophie (Author) / Marvi, Hamidreza (Thesis director) / Ceylan, Hakan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Chemical Engineering Program (Contributor)
Created2023-12
Description
Microbial dysbiosis is a condition where one’s gut bacteria colonies and species are imbalanced due to infection, antibiotics, and diet. Dysbiosis can lead to chronic illnesses like inflammatory bowel disease where current clinical treatments, such as probiotics and fecal matter transplant, have limitations from precisely delivering the right bacteria species in the right location in the gastrointestinal tract. With recent developments of magnetically actuated endoscopy bots which are precisely controlled and less invasive, magnetically-controlled robotic solutions can be applied to solving microbial dysbiosis. Two GI bot designs were developed, an accordion and concertina design, which differ in geometry. These designs involved a soft Ecoflex body, four ring magnets that are made of NdFeB and Ecoflex (in a 4:1 weight ratio) and magnetically actuated in the same direction, and a 3D-printed plastic capsule. The design rationale involved introducing the GI bot to external magnetic fields to deliver a payload, i.e. bacteria, for an application in solving microbial dysbiosis.
First, the design was optimized. Tensile and compression testing were used to determine an optimal Ecoflex coating combination with Ecoflex 00-10 making the first layer and Ecoflex 00-50 making the second layer. Afterward, two main functions were tested for in the robot: (1) precise magnetic control of the robot’s movement and direction and (2) magnetic control of the GI bot’s compression to trigger a payload release. Orientation control of the GI bot was demonstrated with a robot arm introducing a magnetic field of 4.08 mT. The test demonstrated proper control of the robot for five degrees of freedom. Lastly, delivery capabilities for the designs were established under a 173 mT external magnetic field with the accordion and concertina having dyed water (payload) release efficiencies of 35.33% and 40.16% respectively. From these results, a GI bot in the gut is achievable, and the accordion or concertina models provide a basis for further exploring and optimizing the safety and efficiency of this clinical robotic and magnetic solution. Moreover, the results showcase that magnetic actuation can be used for both orientation and delivery control as they are decoupled based on the external magnetic field strength.
ContributorsNguyen, Sophie (Author) / Marvi, Hamidreza (Thesis director) / Ceylan, Hakan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Chemical Engineering Program (Contributor)
Created2023-12
ContributorsNguyen, Sophie (Author) / Marvi, Hamidreza (Thesis director) / Ceylan, Hakan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Chemical Engineering Program (Contributor)
Created2023-12