Project Overview
Nanofibers are a significant part of nano bioengineering, because of their various potential applications. Nanofibers are being used in
many disciplines, ranging from water filtration to tissue engineering
scaffolds. There are many methods to make nano fibers, but electrospinning is one
of the top choices, since it is cost effective and long, continuous nanofibers
can be produced.
Basically, an electrospinning
set-up contains a pipette contained the polymer solution, two electrodes with a
DC voltage supply in the kV range and a collector, as shown in Figure 1. However, there are many
others parameters that affect the electrospinning process such as: humidity and
temperature. Many polymer solutions require hazardous solvents, which
easily vaporize. Current low-cost equipment, which has insufficient protection
features, make changing the distance between the syringe and the
collector and changing the polymer solution very inconvenient tasks. Electrospinning equipment,
which meet all the safety standards, are much to costly for most labs to afford. The proposed design plans is to design a less costly, safer and more convent electrospinning set-up.
Figure 1: This picture shows an elctrospinning apparatus used in the Materials Science and Engineering labs at Drexel University. It is an example of a typical electrospinning set-up that many labs use.
Design
Constraints
The process of electrospinning is used to create nanofibers that can be used for a multitude of different purposes.
However, the electrospinning process is riddled with variables, and very
minimal changes in certain environmental and technical factors can cause an
unsuccessful outcome [1]. Safety, time, and cost are also important constraints that need to be adhered to by the design. The concept behind this design was to lessen the
variables affect on the electrospinning process by trying to keep them as
constant as possible. The following bullets outline the specific constraints of the design:
- Humiduty control [2]
- Safety and ease of use for the user
- Size of the apparatus
- Time it takes to create the set-up
- Cost-effective production of the set-up
Pre-existing Solutions
There are many solutions that are similar to the purposed design that will be developed in the next seven weeks. All
of these solutions would help to remove some of the safety hazards and would
also help to make sure that the process is more precise. One company, Nanospider
[3], has created an electrospinning devise that spins without a needle, it does
this by using wires that are dipped into the polymer solution then are moved
towards the collection plate. Another company that closely resembles many of
the ideas that are being proposed is NanoFMG [4]. This company also has a
needle-less spinning set-up, shown in Figure 2, that would allow for safer collection of the
fibers; however, this design as well as the Nanospider design lack temperature
or humidity controls and other features that make the proposed design novel.
Although these designs are helpful in envisioning the purposed design they do
not completely meet the criteria set forth for this design. In general they
lack ways to monitor and control environmental variables that adversely affect
the electrospinning process, and are not financially viable for most
universities and secondary schools. The design proposed will be new and
innovate because it will be a cost effective and safe alternative to some of
the solutions that are already available and used at Drexel University.
sophisticated set-up that allows for eliminations of some variables that may cause inconstant nanofiber production.
However, this apparatus does not offer any control over the humidity or temperature of the electrospinning vicinity.
Design Goal
The
goal of this design is to improve the safety and ease of use of a low-cost
electrospinning setup, and therefore increasing efficiency and productivity.
Electrospinning can be used to create nano-scale polymer threads of several
different types of materials but this project is focused on spinning
bio-compatible polymers like chitosan for use in biomedical engineering
purposes like cell scaffolds for the anchoring of cells during tissue
engineering procedures.
There
are several issues with current electrospinning setup’s we have seen. Safety is
a major concern, as sharp needles and possible toxic gases and solvents are
used in the process. This design will be addressing this by creating a setup
where the needle pumping out the polymer being spun and the collecting unit are
isolated in their own environment, and an airtight door will allow easy access
to the components right in front of the user without any excessive effort, for
easy changing of needles or collecting of samples. The syringe pump will be
attached to a track so it can easily be moved to the ideal distance from the
collection unit and a ruler will help to determine the distance it is at. A
computer controlled interface that would allow the user to control all of these
variables is a possibility that the purposed design will look into, but it is
not necessary to reach the design goals.
Environmental
conditions are also a large concern, and the design will have a way to tackle
that. Since the electrospinning components are isolated to their own
environment it will be much easier to keep it at the ideal conditions. Humidity
will be controlled by a dehumidifier unit and usually room temperature is
sufficient, so temperature control isn’t as crucial of a factor, but a means to
record temperature will be equip to the electrospinning station. An attachment
to a fume hood will safely dispose of any toxic fumes. Holes drilled in the
bottom of the setup and in the top of the inner chamber will allow air flow and
stop the creation of a pressure differential that could happen with the fume
hood running and no air intake.
Project
Deliverables
Based on the researched complaints and grumbling about the electrospinning process, a set list of deliverables has been developed with the theme of reducing the amount of volatile variables in the electrospinning process. Of all the problems, the ones deemed the most important are address in this design and include: the inability to regulate humidity, inconsistency of the distance between the needle and the target after every process; the bothersome fumes emitted into the air. The project deliverables are: a way to regulate humidity, preferably with the use of computer technology; some kind of apparatus (possibly a track) that would either hold the needle in place, or allow it to slide in and out of the box; and finally a method of directing the fumes emitted to the fume hood in the lab. The deliverables mentioned will be presented in a 3-D Pro-Engineering model of the design. This model will be the visual representation of the improved electrospinning apparatus that will be presented in the final week.If all the deliverables have been met, the design could then be focused on the idea of a computer interface controlled process.
Based on the researched complaints and grumbling about the electrospinning process, a set list of deliverables has been developed with the theme of reducing the amount of volatile variables in the electrospinning process. Of all the problems, the ones deemed the most important are address in this design and include: the inability to regulate humidity, inconsistency of the distance between the needle and the target after every process; the bothersome fumes emitted into the air. The project deliverables are: a way to regulate humidity, preferably with the use of computer technology; some kind of apparatus (possibly a track) that would either hold the needle in place, or allow it to slide in and out of the box; and finally a method of directing the fumes emitted to the fume hood in the lab. The deliverables mentioned will be presented in a 3-D Pro-Engineering model of the design. This model will be the visual representation of the improved electrospinning apparatus that will be presented in the final week.If all the deliverables have been met, the design could then be focused on the idea of a computer interface controlled process.
Project
Schedule
Week Two: April 9th - April 15th
Week Two: April 9th - April 15th
- Set up blog site, give all members access
- Obtain biographical information and contact info
- Divide responsibilities and each individual conducts preliminary research
- Group meet-up on Sunday to present discoveries/research to group members and divide up proposal responsibilities
Week Three: April 16th - April 22nd
- Each individual member should go more in depth into research of their responsibility.
- Visit to the Lab to see more in depth electrospinning and ask questions, take measurements, etc.
- Research as a group complaints brought up by other scientists about the electrospinning process
- Group meet-up on Wed. to combine and edit proposal components
- Update Project Web-site
(The remaining weeks
should focus on completing the deliverables, and expanding the ideas the group
has for this project. )
Week Four: April 23rd
- April 29th
- Address humidity control issue: portable vs. standing dehumidifier.
- Consider what design would work with the choice humidifier we choose
- Begin to contact companies about pricing and recommendations and other options
- Update Project Web-site
Week Five: April 30th - May 6th
- Update project Web-site
- Group meet-up on Wednesday
- Address safety issues
o Read
up on lab technicians/scientists’ safety concern about the needle and the box.
o Come
up with/ expand on ideas to improve the safety of the process
Week Six: May 7th -
May 13th
- Group meet-up on Wednesday
- Review rubric and fine tune blog.
- Make sure all the criteria are met
Week Seven: May 14th - May 20th
- Address emitted fumes issue
- Document reports of fume damage to a project or persons
- Update Web-site
- Draft options choose and fit the solution to our design
Week Eight May 21st - May 27th
- Group meet-up on Wednesday
- Update Web-site
- Finalize new design
- Make the Pro-E model
- Based on required parts for model, compile a list of costs associated with project
Week Nine: May 28th - June 3rd
- Group meet-up on Wednesday
- Address any technical issues
- If project went over budget, look for cheaper alternatives to parts.
- Fine tune Website- use rubric
Week Ten: June 4th -
June 10th
- Presentation of New design to TA and Faculty Advisor
Budget
Table 1: This table represents the materials needed to create the proposed design. It includes the prices, amounts of each material needed, and hyperlinks to the retailers that sell each material. There is also a brief explanation of why each piece is necessary to the design.
Item
|
Quantity Required
|
Price Per Unit
|
Where Unit are Purchased
|
Brief
|
Dehumidifier
|
1
|
$81.39
|
| |
Arduino Software
|
1
|
$650.00
| ||
Door Hinges
|
2
|
18.99
|
| |
Syringe Pump
|
1
|
$275
|
| |
Gamma High Voltage Power Source
|
1
|
$5000
|
| |
Mini door handle
|
1
|
$2.99
|
| |
Rubber door seal
|
1
|
$8.89
|
| |
Plexiglass
|
1 (32 ft2)
|
$213.68
|
| |
Total:
|
$6,250.94
|
Citations
[1] Y. Liu, J.H. He, J.Y. Yu, H.M. Zeng, "Controlling numbers and sizes of beads in
electrospun nanofibers," Polym. Int., 57 (2008), pp. 632–636
[2] C.J. Thompson, G.G.
Chase, A.L. Yarin, D.H. Reneker, "Effects of parameters on
nanofiber diameter determined from electrospinning
model," Polymer, 48 (23) (2007),
pp.
6913–6922
[3] Liska. (2004). Elmarco
[Online]. Available: http://www.elmarco.com/
[4] Nanofiber membranes
group [Online]. Available:
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