Project Overview-
Electrospinning was a process widely used to create nanofibers with a liquid polymer. A standard electrospinning apparatus consisted of a power supply, a syringe filled with the liquid polymer and a grounded metallic sheet to catch the fibers. The formation of these fibers was done through placing the syringe through an electric field. “When the voltage reaches a critical value, the electric field strength overcomes the surface tension of the deformed polymer droplet, and a jet is produced” [1]. As the electric field intensified, the liquid polymer was drawn from the syringe and projected towards the grounded metallic sheet [1]. After a lengthy duration, the culmination of the liquid fiber on the metallic sheet would dry and could be used for various purposes.
Jennifer Atchinson designed an electrospinner out of K’Nex pieces. The goal was for this design to be an instructional tool to introduce high school students to materials science. The main objective of this project was to optimize the electrospinner that Jennifer Atchinson created by adding the ability to modify the speed of the device’s motor. The effect of speed on the yield and quality of the nanofibers collected was then observed in order to assess the effectiveness of the modifications. Other objectives considered were creating a custom well plate and adding a conveyor belt to the top of the device.
Design Constraints-
Several limitations to the overall design of the electrospinner were presented. As an educational tool, the electrospinner had to be produced at minimal cost, and able to be transported easily. For these reasons, the design of the electrospinner was restricted to be constructed out of K’Nex pieces. K’Nex pieces are relatively cheap and were relatively easy to take apart and reassemble. Furthermore, because the electrospinner was used in high schools, the design needed to be safe to avoid potential hazards.
Pre-Existing Solutions-
Several methods of performing electrospinning already existed. Traditional electrospinning apparatuses made use of a syringe with a metallic needle to project polymer [1]. Other systems existed that used a turning wheel to project the polymer [2]. The problem with these two electrospinners was that they were not accessible to the public due to their cost. The concept of a portable electrospinner for educational uses had not been an area deeply explored. Prior to this experiment, there was only one electrospinner that was capable of fulfilling most of the constraints. The prior electrospinner design had worked sufficiently, in both producing nanofibers and working as an educational tool. Jennifer Atchinson was inspired to construct the electrospinner after seeing a industrial model used by Nanoforce Technologies [2]. Since her design was only constructed with K’Nex parts, the design was easily constructed, cost-efficient and portable. The electrospinner did have low manufacturing cost and was capable of producing small amounts of nanofibers for demonstrational uses. However the design did lack in several areas, which included safety and control of the motor speed.
Design Goal-
The final goal for the project was to optimize an electrospinner design solely made out of K’Nex parts. The constraints of portability, cost, and material were fulfilled by using K’Nex parts. The K’Nex parts are detachable and could be procured for a minimal fee. As for the other constraints, a manual gearbox was to be created in order for the electrospinner to have variable speeds. The gearbox would allow for the user to choose a preferred speed by adjusting the gear ratio. The safety of the user would also be handled by encasing the copper wire with a rubber cover to prevent any accidental electrocution. A custom well plate was produced for the device. A conveyor belt was added to the top of the device in order to increase the amount of nanofibers collected. These goals were chosen based upon the time constraints and materials available.
Project Deliverables-
The culmination of the project would yield several deliverables. Primarily, it produced a fully-functional electrospinner, composed of K’Nex pieces, that was able to perform at 3 different speeds to successfully produce nanofibers. The next deliverable produced was nanofiber samples taken from low, medium, and high gear speed settings. In addition to the samples, micrographs of these samples were obtained. An analysis of the micrographs of the resultant nanofibers was needed to assess the effectiveness of the changes to the original model. The blog was updated weekly and it tracked the progress of this project. The last deliverable was a report that discussed the entire project.
Project Schedule-
· Week 3 –Design Proposal Completed, Second Electrospinner Constructed, Weekly Blog Updated, Electrospinning Research Completed, Testing of the Control Group Completed and Initial Well Plate Design Completed
· Week 4 – Materials Obtained, Fast Gear Design Completed, Well Plate Created, Weekly Blog Updated
· Week 5 – Fast Gear Setting Tested, Design of Slow Gear Completed, Weekly Blog Updated
· Week 6 –Slow Gear Setting Tested, Design of Gearbox Completed, Weekly Blog Updated
· Week 7 – Construction of Gearbox Completed, Gearbox Design Tested, Weekly Blog Updated
· Week 8 – Analysis of Samples Completed, Initial Conveyer Belt Designed (Optional), Weekly Blog Updated
· Week 9 – Initial Conveyer Belt Testing Completed (Optional), Final Report Drafted, PowerPoint Presentation Started, Weekly Blog Updated
· Week 10 – Final Report Completed, PowerPoint Presentation Completed
Project Budget-
· 250g 300,000 Da Polyethylene oxide (Sigma Aldrich), Item # 182001 - $113.50
· Thread - $5.00
· Batteries - $5.00
· 521 Super Value Tub (K'Nex), Item # 12575 - $25.00
· 2 Battery Power Packs (K'Nex) Item # 92880 - $16.77 each
References
[1] Frank K., Ko (2005). Electrospinning [Database] Available: http://www.accessscience.com/content.aspx?searchStr=electrospinning&id=YB052270
[2] Nanoforce Technologies. (2010 April 18). Electrospinning with Nanospider @ Nanoforce Lab [Video File]. Retrieved from http://www.youtube.com/watch?v=9_7bevTse4E
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