In the past few decades, the medical field has shown a great increase in preference for minimally invasive procedures. The benefits of these types of procedures have led to the development of micrometer scaled magnetic objects called untethered magnetic robots (UMR). Much research has been conducted on UMRs, but in the past decade the topic of biodegradability has come to be heavily researched. Much was still unknown about the performance and degradation of biodegradable UMRs.
This thesis focuses on the influence of flow on the degradation rate and lifespan of biodegradable, sugar-based, nanoparticle UMRs. During this thesis, UMR swimming tests in ethanol, UMR mass degradation tests, CT-scan degradation tests and flow degradation tests were performed. The results showed increased UMR swimming performance at Rotating Perma-Magnet (RPM) distances of 4.5 to 5 cm and at RPM frequencies of 5 Hz. The results are unclear as to whether UMR degradation rate in saline is comparable to that in blood. CT-scan footage showed clear UMR visibility over an extended period. Flow degradation tests showed an increase in degradation rate as flow increased up until 150 mL/min. When flow was increased further, the degradation rate seemed to slightly decrease. Due to high standard deviations, an eventual decrease in degradation rate was still unclear.
These findings suggest improved UMR swimming performance at lower RPM distances and frequencies. They also imply the ability to use computed tomography in further testing and potentially in real-world biodegradable UMR applications. Lastly, the UMR degradation rate can be concluded to increase up until a certain flow value, with higher flow values still being unclear.