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An electrospinning machine (EM) produces fibers and particles by means of applying a voltage process (electrohydrodynamic phenomena) to a polymer solution by incorporating the use of a receptacle, a pump, a high voltage power supply (HVPS) and a collector.
EMs are typically very expensive, however, there has been work conducted by various researchers to construct in-house machines at a much lower cost. The growing applications for electrospinning continue to be a source of interest for many researchers as it is still a relatively new process. Much of the effort has been dedicated to producing nanofibers with unique properties with a focus on improving the efficiency and scalability of the process.
The Electrospinsters Senior Design Team are researching and designing an in-house EM that can produce nanofibers for the team sponsor’s research and serve other educational purposes at Trinity University. The sponsor, Dr. Dany Munoz-Pinto, intends to use the results of this project to expand his research projects and goals by incorporating nanofibers into tissue scaffolds. The prototype must be a functioning EM so that a future team or the sponsor’s research students can make additions, but not struggle with the basic functions to create nanofibers.
Based on published literature and additional research conducted by the team, we determined that an EM is composed of four subsystems: a syringe pump, a HVPS, a collector, and a user interface. The HVPS provides a voltage to the solution in the syringe pump which when exuded is drawn to the grounded collector due to the difference in electric potential. This drawn-out solution conglomerates on the collector which forms the scaffold. Published literature allowed us to gain a better understanding of the setup and we learned that there is not much variation in how the EM can be modified. Consequently, we chose to follow a fundamental setup with a flat collector plate due to its easy construction and compatibility with producing non-woven nanofibers with polyvinyl alcohol (PVA).
We designed and conducted a series of tests to validate the subsystems of the device and to test the EM against various design constraints and project requirements. Some of our constraints pertained to time and budget and our project met both of these, as we successfully created a working prototype for our sponsor by the end of the 2023 spring semester, and we only used $808.92 of our $1200 budget. Other criteria related to health and safety were met, since we complied with TU Environmental Health and Safety and OSHA standards, the voltage applied to the solution did not exceed 30 kV at any point during testing and application, and our device fit dimensional constraints and was only operated in a CSI fume hood to prevent the inhalation of nanoparticles. Our prototype operates all electrical subsystems using US standard outlets. Certain requirements correlated with certain subsystems which had specific tests designed to evaluate the flow rate, voltage, voltage display, and nanofiber diameter. The Flow Rate Variability Test evaluated the syringe pump subsystem with variable flow rates of 0.5 mL/hr, 1.0 mL/hr, and 1.5 mL/hr and deemed accurate enough for testing purposes. The Voltage Variability Test tested the active voltage of the HVPS and verified its operation is within a ±5% margin of error. The Proof-of-Concept Test verified that the EM could produce non-woven nanofibers of 200 nm and that it is within ±20% error of previously published experiments, which are acceptable results for our sponsor’s research purposes. Additionally, we tested Tip Diameter Variability and Collection Distance Variability to observe the effects on the nanofiber diameter and determined that there is not a significant difference as they are still within ±20% error, as we had expected from published literature.
Overall, the Electrospinsters created a successful, working prototype to aid in our sponsor’s research. Our prototype met all requirements and constraints, and there are no remaining changes needed to achieve our final goals. However, for further improvements, we hope that a future team will improve this final prototype by integrating another type of collector that can produce aligned nanofibers while maintaining the ability to interchange collector types and implementing any other useful additions or modifications.
Amaya, Gerson; Cruz, Andrea; Gonzalez, Anna; and Riley, Lucas, "Electrospinsters Final Project Report" (2023). Engineering Senior Design Reports. 60.