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<ul class="nav navbar-nav ml-auto">
<li class="nav-item">
<a class="nav-link" href="#fabes1">FAB-ES #1</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#fabes2">FAB-ES #2</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#fabes3">FAB-ES #3</a>
</li>
<li class="nav-item">
<a class="nav-link" href="#fabes4">FAB-ES #4</a>
</li>
</ul>
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<h1 class="text-sm-center">2000x Fab Spinning Machines<br>
<small class="text-muted">DIY Filter Media Production on a Global Scale</small>
</h1>
<br><br>
<h5 class="text-sm-center">by Filippos Tourlomousis, Camron Blackburn, Jiri Zemanek, Zach Fredin and <br> Neil Gershenfeld</h5>
<h5 class='text-sm-center'>The Center for Bits and Atoms, MIT</h5>
<hr>
<h2 class="text-sm-center">Problem</h2>
<p class="lead text-justify">
shortage of respiratory filter Media
</p>
<h2 class="text-sm-center">Proposed Solution:<br> <small class="text-muted">90 countries = 2000x Fab Labs = 2000x Fab Spinning Machines</small></h2><br>
<h2 class="text-sm-center">Research Question</h2>
<p class="lead text-justify">
- rapid prototyping
- high throughput
- high quality factor
- high surface to volume ration (no post porcessing)
- control reproducible fiber diameter - porosity
</p>
<h2 class="text-sm-center">Fab Spinner Concept</h2>
<h2> <small class="text-muted">Sketch:</small></h2>
<img src="img/cotton-candy-sketch.PNG" class="rounded mx-auto d-block" width="90%">
<h2> <small class="text-muted">CAD:</small></h2>
<h3>A. Filters: Design Specs</h3>
<p class="lead text-justify">
We aim to rapidly fabricate membranous filter media against the COVID-19 virus while minimising
breathing resistance in respiratory applications.
Our design goals are to maximise COVID-19 filtration efficiency and minimize pressure drop (air flow
resistance) across the membrane so that the patient doesn't have to work too hard to breath.
<br>
<a href="https://gitlab.cba.mit.edu/camblackburn/filter_testing#fn2-7883" class="text-primary"
class="nav-link"> Filter Testing Metrics from Camron</a>
</p>
<p class="lead text-justify">
Commercial respiratory filter media that meet regulatory metrics are linked HERE: <a
href="https://www.intersurgical.com/products/airway-management/floguard-low-resistance-breathing-filter-for-cpap-and-bilevel#downloads"
class="text-primary" class="nav-link">
Commercial Flo-Guard Breathing Filters</a>.
</p>
<br>
<img src="img/comm-filter.PNG" class="rounded mx-auto d-block" width="70%">
<br>
<p class="lead text-justify">
Commerical respiratory filters are made from these materials......
</p>
<br>
<img src="img/filter-open.PNG" class="rounded mx-auto d-block" width="40%">
<br>
<p class="lead text-justify">
Specific design goals metrics are listed below.... These are based on ....
</p>
<hr>
<h2>B. Process: Electrospinning</h2>
<br>
<p class="lead text-justify">
To adress a possible outage of commercial respiratory filters due ot the CVD pandemic, we propose the
design of machines for the production of nonwoven fibrous
membranes made from inorgancic polymer composites with the electrospinning process. Electrospun
membranes can be employed as antiviral filter respiratory media
in protective equipment against the CVD-19 virus. The benefits of electrospun membranes over
conventional filter media media are:......
The electrospinning process is simple... The challenge is throughput...
but is solvable... explain why...
</p>
<img src="img/filter-es-production.PNG" class="rounded mx-auto d-block" width="90%">
<br>
<p class="lead text-justify">
The electrospinning process is based on the electrohydrodynamics phenomenon, where a material
substrate loaded within a syringe with a charged needle tip attached to it and pointing towards
a grounded collector, is extruded and subsequenlly stretched using a high volatage potential.
Assuming that the material substrate is viscoelastic enoough and as soon as the electrostatic
stresses
overcome the surface tension of the material, fibers in a chaotic motion are deposited on the
collector.
The fiber formation mechanism is shown in the video below:
</p>
<video width="800" height="600" style="display:block; margin: 0 auto;" controls>
<source src="img/electrospinning-amazing-video-smaller.mp4" type="video/mp4">
</video>
<br>
<p class="lead text-justify">
The two main types of electrospinning process are: a) solution electrospinning (SES) and b) melt
electrospinning (MES). This classification is based on the material form used for processing; with
SES using
a polymer solution (pellets/powder mixed with solvent) and MES using pure polymer melt without any
chemical solvents.
The 3 main common system components for both process types are: a) the extrusion device that can be
either
mechanical using a syringe pump or pneumatic, b) a high-voltage power supply and c) a collector that
in
the most basic setup is a flat grounded aluminum plate.
</p>
<br>
<img src="img/ses-vs-mes.PNG" class="rounded mx-auto d-block" width="80%">
<br>
<p class="lead text-justify">
Different types of nozzles and collectors assembled either in a horizontal or vertical
configuarations have been
reported in the literature leading to different types of electrospinning processes. Each
electrospinning process
has advantages and disadvantages depending on the application.
</p>
<hr>
<h2>C. Which is the most suitable type of electrospinning process for repsiratory folter media production?
</h2>
<p class="lead text-justify">
ENM can be potentially employed to filter a variety of pollutants. ENM can capture PM due to a
combination of small diameter,
small pore size and high specific surface area. Moreover, the surface of ENM can be functionalized
to adsorb different VOCs.
Electrospun nanofibres can also be engineered to reduce the pressure drop which is immensely
desirable for respiratory filter media. Carefully engineered ENMs can simultaneously extract harmful aerosols and gases from the air with
minimum air resistance.
This hypothesis is tested in various experiments involving different approaches, viz. beaded
nanofibres, bilayer nanofibres, use of
specific additives, and surface modification of electrospun nanofibres. This research is aimed at
studying ENM as a protective material
against different air pollutants while minimising breathing resistance in respiratory applications
with the following objectives:
[1] To reduce pressure drop (air resistance) across the ENM while maximising PM filtration
efficiency;
</p>
<p class="lead text-justify">
- high-throughput<br>
- multiple nozzles<br>
- rolling collector<br>
- polymer solution for functionalization<br>
- hydrophobicity<br>
- anti-viral material<br>
- fast cheap assembly<br>
</p>
<p class="lead text-justify">
Below in Section "D" we propose 3 different types of electrospinning machines of varying complexity
and capabilities staring
from the simplest one that can be made with off-the0shelf components that might be laying around in
a hospital, moving to a
simple design that reducing the cost, is parallelizable and can be made in a fab lab using a laser
cutter and a 3D printer and
resulting to a slightly more advanced for increaed throughput.
</p>
<hr>
<h2>D. FAB-ES Machine Collection</h2>
<p class="lead text-justify">
Designs with increasing complexity/capabilities
</p>
<br>
<h2 class="text-sm-center" id="fabes1">FAB-ES Machine #1</h2>
<h4 class="text-sm-center" id="fabes1">The simplest ES machine made using mostly off-the-shelf parts
found in a hospital</h4>
<p class="lead text-justify">
<b><u>Parts:</u></b>
<br>
<li>Syringe Pump</li>
<li>Syringes</li>
<li>Needle Tips</li>
<li>Foam</li>
<li>Aluminum Foil</li>
<li>Lab Jack</li>
<li>High Voltage DC Power Supply</li>
<li>Cables</li>
<li>Aligator Clips</li>
<li>Electrical Tape</li>
</p>
<p class="lead text-justify">
<b><u>Tools:</u></b>
<br>
</p>
<br>
<img src="img/img-es-meshes.PNG" class="rounded mx-auto d-block" width="80%">
<br>
<hr>
<h2 class="text-sm-center" id="fabes2">FAB-ES Machine #2</h2>
<h4 class="text-sm-center" id="fabes2">The simplest fabricatable ES machine design</h4>
<hr>
<h2 class="text-sm-center" id="fabes3">FAB-ES Machine #3</h2>
<h4 class="text-sm-center" id="fabes3">Roll-to-Roll Multinozzle Solution Electrospinning</h4>
<hr>
<h2 class="text-sm-center" id="fabes4">FAB-ES Machine #4</h2>
<h4 class="text-sm-center" id="fabes4">Roll-to-Roll Blowing Electrospinning</h4>
</div>
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