Memo
Date: January 26,2015
To: Inst. Bruce Trott and GTA Mohini Dutt
From: Brooke Ott
Group: R
Subject: Introduction to Lab On A Chip
Introduction
Lab-On-A-Chips have a generic design that will influence potential designs for a LabOn-A-Chip to diagnose dry eye. The purpose of experimenting with a generic design was to test
different channels and determine the functionality of the chip design. In experimenting, the
performance of the generic design will be tested and performance of the generic design to
improve upon in future designs.
This includes the results from experimentation with a generic Lab-On-A-Chip design,
discussion of the results determined from testing and a sketch of a design for a Lab-On-A-Chip
idea. This lab was performed by the team of Joshua Epperson, Brooke Ott, Luisa Parish, and
Ben Weisman.
Results
Initially during experimentation, the team determined a numbering system to refer to the
wells on the chip. The team determined that the wells would be number 1 through 5 going
counter- clockwise around the chip starting counter- clockwise of the team logo. This allowed
for the team to correctly determine the functioning of each well and which well performed the
best. It was determined that wells 2 and 3 performed the best while, 1 and 5 performed the
worst. Well 4 performed average compared to the other wells. While putting the top level of the
PDMS chip on the chip, the holes did not properly align with the wells. The wells with the
holes correctly placed performed the best overall during the experiment. The check valves
seemed to perform correctly and allowed for the fluid to stop for a second. However, the check
valves did not make a noticeable difference in the performance of the wells.
During the experiment, it was observed that the pressure was often released as the syringe
was being removed. This was despite attempts to maintain a constant pressure on the PDMS
chip. While, the syringe was being inserted and releasing the fluid the pressure was maintained
however, the wells often over flowed once the pressure was released. This caused difficulties
during experimentation.
Discussion
There are several issues preventing the proper use of this chip. A major issue preventing
the proper use of this chip was that as the syringe was removed the pressure was released
allowing for the fluid to leave the well. Another issue involving the wells was that the cover was
not properly in line. This made it difficult to insert the fluid causing it to over flow if it was not
centered over the well. This prevents the chip from being properly used.
Cleanliness can be maintained during experimentation if the chip is flushed out after
every test that is done. This will prevent confusion in determining the abilities of certain wells
and their reactions. Another practice to ensure cleanliness is to make sure that a petri dish is
cleaned before being placed under the chip during experimentation. This will ensure the control
of fluid from overflowing the container. This would allow for the team to keep the chip as
sanitary as possible during experimentation. The cleanliness of the environment would be
maintained by adopting these simple practices during experimentation.
The chip should be used with a few external devices in order to improve quality. To
improve the cleanliness, gloves, paper towels, and a sink should be used in order to rinse out the
wells and dry them to allow the team to see the experimental process better. The gloves should
be used, they are used in order to keep the dish sanitary and save the user from a chemical spill.
In order to improve the detection, the light underneath the chip was helpful to improve the ease
of seeing the fluid movement in the chip. The chip should be transported during the lab using
rubber gloves and in a petri dish. This is required because otherwise if the nano chip is dropped
at some point the petri dish would be easy to find as opposed to a nano chip. In order to store the
chips, a closed container should be used with only the chip in the container. These are important
in order to make the chip easier to find and keeps it clean when storing.
If this chip performed correctly and was available for purchase, it would only have a few
applications. The application would be to collect different fluids in a controlled environment and
see how they react with one another in a controlled environment where the initial reaction could
be viewed. This may be useful to collect multiple fluids and watch how they flow at these levels.
The chip could be improved to perform better through a few variations. If the wells lined
up correctly with the design, that would improve the ability of the user to insert the fluid into the
chip. I think that all of the wells should have an incline in the back of the well. This was in
wells 2 and 3 which were the best performing wells. This would allow for it catch some of the
fluids in the well. I would try to keep the wells on the opposite side of the waste well because it
seemed that those performed the best. These are the ideas to improve on this design to allow for
it perform better in application.
Questions
Nanotechnology allows for improvements that current scientific approaches do not allow
for. The nanotechnology offers a future in defense, medicine, and consumer products. These
capabilities are available because matter performs differently at the nano level. At the atomic
level, materials follow quantum laws while, at the visual level, materials follow principle laws.
These allow us the opportunity to work on the nano level for defense purposes to sense chemical
and biological warfare as well as increasing materials performance and affordability. As a
medical application, nanotechnology could be used to diagnose diseases as early as the first few
cells being formed. It would also lend its use to treating diseases by targeting the specific
diseased cells as opposed to the entire body. The nanotechnology can be used to improve
consumer products by improving the materials in products to be more durable which would
improve the quality of products and hopefully make products more affordable. Nanotechnology
has several applications that will hopefully be applicable in the nearby future.
Particles perform differently on the nano scale then bulk materials because they are
between laws. Scientists have not studied this scale long enough to determine a set of rules that
identify a materials behavior at this scale. On a bulk scale, materials follow a set of basic
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principles while, on an atomic scale materials follow principles of quantum mechanics. The
nano scale is closer to the atomic scale but does not fit into either principle. If scientists can
create an understanding of the nano scale, there is hope for many changes on the future to
various applications. A current application of nanotechnology is in Wilson Double Core TM
tennis balls. The nanotechnology is used in the tennis balls to slow the release of air making
them last longer than a tennis ball without the use of nanotechnology. While the future
applications of nanotechnology play a role in American defense, the US is investing money in
nanotechnology in order to build a suit that will allow to sense chemical warfare, that is more
durable and storage. Nanotechnology offers hope for future applications as well as already
offering improvements in consumer products.
Initial Chip Design Sketch
Please refer to the attached sketch of the initial chips. This chip is a square with 2 staging
wells, a detection well and a waste well. This design has check valves to control the flow of the
fluids. The fluid will be inserted into the staging wells, will pass through a check valve, and
continue on to a detection well before returning to a waste well.
This design has several unique features that vary from the generic chip. The shape of the
chip is a rectangle because it allows for the top layer to only have one proper fit making it easier
to align the correct wells with the holes for the syringe. The waste well is four times bigger that
the two staging wells combined in order to hold all of the excess liquid and allow for multiple
tests if necessary. The detection well is an ellipse because it will catch some of the liquid but
will not prevent the flow. The staging wells have an incline in the back in order to catch the
fluid and prevent it from overflowing.
Conclusion
The goals of the experimentation was to familiarize the team with the use of this
technology, as well as, offer a generic design to improve upon in future experimentation and
trials. The fluids allowed a look at how the fluids would flow at this small of a level to offer an
idea for the future. A necessary part of this experimentation was to allow for the use of a syringe
to insert fluids into these environments properly. The experiment offered a look and chance to
become familiar with the environment for future experimentation of a Lab-On-The-Chip.
The environment is essential for performing proper procedure. The proper equipment
allowed for precision in the lab and for the chip to perform at its best. Procedure is important to
ensure that the chip is tested in a similar way for every step of the process. It ensures that the
chip is being used for the purpose it was intended for. This allows for the chip to perform
properly under the conditions it was intended for. While the work environment is important as
well, this ensures that the conditions are cleanly and consistent. The environment allows for
easy replication and comparisons because outside factors are limited.
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