Design Proposal

Problem Overview

            Electrospinning is a chemical process that uses an electric field and a chemical solution to create polymers in the form of nano-fibers. A liquid solution is created based on its properties which should be appropriate for the intended application of the fiber. A drop of the solution is then exposed to an electrical field whose force breaks it surface tension and creates a stream. As that stream travels in the air, it solidifies and gathers on a collector plate as a solid nano-fiber material.

The unique process of electrospinning was developed no more than two decades ago as a process which made the creation of nano-fibers affordable and possible with limited resources. It is now widely used for a great variety of purposes. Among them are the use of nanofibers in medicine, textiles, filtration, and agriculture.

As many more uses are being developed for electrospinning, it is imperative that the process itself also develops to account for the need of rapid and convenient ways to create nano-fibers. While the process itself is already relatively simple, it does take up some space and requires a series of devices working in conjunction with each other. The ideal development in the process of electrospinning would be to have it done completely using a single, portable device. This is the motive behind the project proposed.

A portable electrospinning device would allow for the easy application of nano-fibers onto any surface desired. This device would expedite the electrospinning process and open up an abundance of opportunities for its application.

Design Constraints

     The electrospinning device must be made of a plastic or insulating material due to the nature of electrospinning. For the phenomena to take place, the electromagnetic fields need to be controlled and applied very specifically. There should only be three conductive materials would be the grounded plate on which the fibers collect. The second being the tip of the delivery system, whether it be syringe or some other method. Lastly a device for controlling the direction of the fibers onto a desired target. A small motor could be used for this task.  Plastics seem to be the best route as it is lightweight, durable, yet will sufficiently insulate the electrospinning phenomena. The device will be powered by a regular wall outlet.
     Some possible variable controls that could be implemented in the design would be the ability to vary distance between the medium delivery system and the grounded plate. Varying distance is the easiest way to change the diameter of the nano-fibers. Also the ability to change the temperature and relative humidity within the unit to achieve conditions conducive to electrospinning. Finally, some simple electronic devices will be implemented to regulate all of the conditions within the device as well as controlling the potential difference that would essentially discharge the fibers onto a target.

Pre-existing Solutions

    The only current portable applicator is a hand held electrospinning device fabricated by students of the Nation University of Singapore (NUS). The device resembles a space age hair dryer and is a gun shaped applicator that spins the fibers by the pulling of a trigger. In total, the device fundamentally consists of: reservoir for holding electrospinning medium, outlet at front for dispensing of fibers, grounded electrode by which to collect fibers, hollow elongation device adapted to be connected to electrical outlet which is capable of directing the dispensed Nano-fibers. The device is said to be somewhat of a cross between a commercial electro-spray device and a commercial electrospinning device. The key technological advances noted by the students would be the portable, light-weight design and easy to apply mediums, an exchangeable reservoir delivery system to make one device effective for multiple applications, and fibers fabricated through the process of electrospinning. The advantages to their design are that it is environmentally friendly; easy to use which enables the device for household use or low scale industrial use and research, and finally the portability is again one of the biggest advancements in the field of electrospinning.
    In addition, commercial solutions exist for the large scale manufacturing of textiles such as kevlar or nylon.  These companies use a larger scale methods based on electrospinning to mass produce these products.

Goal

            The major difference between the device proposed and the pre-existing electrospinning process is that it is all inclusive: all of the components necessary to create the nano-fibers are contained in a single device.

            In contrast to the traditional way to carry out the process, the device will be hand held and portable, whereas the traditional way necessitates that it be done in a stationary environment.

            The traditional method of electrospinning makes uses of many different apparatuses. A syringe is filled with solution and fitted into a syringe pump which is plugged into an outlet. A conductive wire is connected between the metal tip of the syringe and a voltage generator. Positioned approximately 15 centimeters away from the tip of the syringe is a collector plate held up by a clamp. All of these pieces of equipment must be individually calibrated before the process begins and they must remain stationary throughout.

            The proposed device will run on battery power and will contain all of the components or alternatives to the components described above. The handheld device will generate its own voltage using a capacitor charged by the battery. The voltage will run through a metal rod which protrudes from the front and which also releases the solution. The solution would be first loaded into a canister that fits inside the device. A button or switch would then cause the current to flow, creating the electrospun material. The collector plate can be substituted by any surface which suits the purpose of the applicator.

Project Deliverables

The ultimate goal of this project is to build a portable electrospinning device that can produce nano-fibers. The first step is to create a simple prototype of electrospinning model using a K'nex kit. Once this is achieved, the next stage is to improve and change the model into a portable device that can direct the fibers onto targeted surfaces for different applications.  Parts can be fabricated from the local machine shops.  

Project Budget

Black Nylon Threaded Rod - $4.26

Self-Lubricating Turcite Acetal Rod - $6.55

Applied Motion Stepper Motors - $47.25

Arduino Development Boards & Kits - AVR - $25

Weekly Schedule

Week	Deliverables
3	Design Proposal
4	Collect materials/equipment needed Design the structure
5	Building the Prototype
6	Testing and Revisions
7	Prototype Completion Fabricating Final Design
8	Building, Testing, Revising Final Design
9	Final Design
10	Final Report Final Presentation