One of the limitations we identified early on in our project was the lack of concise and clear information about microfluidics for researchers in Synthetic Biology. Using the iGEM poll we were able to confirm this suspicion and understand what the synbio community wanted us to design for them.
As a result, the first stage of MARS is increasing the understanding of microfluidics. Under this section we have included a brief introduction to microfluidics as a whole and an explanation of how our continuous flow devices function. A primitive guide has also been included so researchers can identify and understand the function of each element on their chips. This guide can also be used in conjunction with the software tool 3Duf in order to design your own chip, or to adapt and iterate on our designs in the MARS Repository.
Team:BostonU HW/IntrouF
Microfluidics 101
Contents
Introduction to Microfluidics
What is Microfluidics?
Microfluidics is the manipulation of microlitre volumes of liquid in order to perform scientific experiments. This is performed on devices called microfluidic chips that can be made of polycarbonate, glass or silicone.
What is a Microfluidic Chip?
A continuous flow microfluidic chip typically consists of three layers: a flow layer and control layer with a flexible layer of PDMS between them. There are many other types of microfluidics such as digital or paper which operate using different mechanisms, however we will focus on continuous flow chips as this is the type utilised by MARS.
Material: Polycarbonate
The Control layer of a microfluidic is used to actuate the flexible PDMS layer in order to manipulate fluid flow through the flow layer. For example, by actuating a syringe attached to the control layer, a valve can be opened.
Material: Polydimethylsiloxane The PDMS layer of a microfluidic lies between the flow and control layers. This flexible membrane allows for a seal to be created between the two polycarbonate layers. PDMS can be actuated to manipulate fluid flow in valved designs.
Material: Polycarbonate The Flow layer of a microfluidic is the layer that liquid(s) flow through. Etchings on this layer, known as primitives, are used to manipulate and alter fluid flow. For more information regarding primitives refer to the Primitive Table.
How can Microfluidics Apply to Synthetic Biology?
Microfluidic chips can be designed to perform various procedures used in synthetic biology. However, microfluidics is often an overlooked tool because designing and using chips requires specialized knowledge.
MARS (Microfluidic Applications for Research in Synbio) is an online repository that will host the designs of nine microfluidic chips that perform fundamental synbio protocols as well as tutorials and guidelines for using them. This will make microfluidic chips a more accessible, inexpensive and practical tool for synthetic biologists to integrate into their labs.
MARS (Microfluidic Applications for Research in Synbio) is an online repository that will host the designs of nine microfluidic chips that perform fundamental synbio protocols as well as tutorials and guidelines for using them. This will make microfluidic chips a more accessible, inexpensive and practical tool for synthetic biologists to integrate into their labs.
Primitive Table
| Primitive | Design | Mill |
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Channel
Carry fluid through the chip and between other primitives
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Ports
Used to input or output fluids from a chip. At least two ports are necessary for a single chip, one to input fluid and the other to output it at the end
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Mixer
Mixes two or more liquids together
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Curved Mixer
An iteration on the previous mixer. Mixes two or more liquids together but has improved fluid flow due to its curved design
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3-D Valve
Blocks the flow of fluids through a channel. Can be opened to allow liquid to flow through
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Circle Valve
Used in conjunction with the 3D valve. For any 3D valve on the flow layer, there must be a circle valve placed directly above it on the control layer
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Chamber
Can be filled with fluid for various applications. For example, incubation
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Trees
Allows for fluid to be evenly split into two separate channels
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Transition
Provides a smooth transition point between two primitives of different sizes. For example, between channels of width 800um and 1500um.
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Metering
Allows for accurate volumes to be measured and dispensed. Made up of valves and channels. Multiple metering sections can be used in tandem to measure multiple volumes to be manipulated.
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MARS Tutorial Videos
Summary
In this section you will find our Microfluidics 101 video tutorials. These videos take you through the basics of fabricating and using MARS microfluidic chips. Each is a fully narrated, step-by-step guide teaching you how to mill, make PDMS, and more! For those who prefer reading, each video is accompanied by an in-depth, printable written protocol.
This branch of MARS was validated by our iGEM poll. When we reached out to teams regarding what educational materials they would find useful, one of the highest voted tools were video tutorials with 73.8% of responses indicating video tutorials would help them start using microfluidics. These video ideas were also pitched to various microfluidic manufacturing companies who advised us on various elements to include. For example, including written content in the form of protocols was suggested in order to provide a written guide to be carried into laboratory settings or referred to when offline. For example, inclusion of the “Cleaning” video was inspired by Black Hole Lab’s emphasis on proper cleaning and storage of their chips during training seminars for lab technicians.
This branch of MARS was validated by our iGEM poll. When we reached out to teams regarding what educational materials they would find useful, one of the highest voted tools were video tutorials with 73.8% of responses indicating video tutorials would help them start using microfluidics. These video ideas were also pitched to various microfluidic manufacturing companies who advised us on various elements to include. For example, including written content in the form of protocols was suggested in order to provide a written guide to be carried into laboratory settings or referred to when offline. For example, inclusion of the “Cleaning” video was inspired by Black Hole Lab’s emphasis on proper cleaning and storage of their chips during training seminars for lab technicians.
Milling
PDMS
Assembly
