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Design

Our Hypothesis

We believe that drug testing kits should be safe, affordable, and readily available to those at risk.

Where tests are affordable and understandable to the end-user, accuracy, and thus safety, is compromised. It is clear that the current methods for checking drugs are not adequate. To change this we envisioned a test designed and modelled around the fundamental needs of the users. This is a test built from their personal input and experience, to create the most useful and appropriate device possible.

We see an opportunity for synthetic biology to provide us with the winning combination of accuracy, ease of use, adaptability, low-cost and portability - a mix that neither simple chemical test-kits nor high-end analytical chemistry can provide. Synthetic biology has allowed us to present the best aspects of all the existing methodologies in one simple device, creating a feasible method of getting accurate safety information to all those who need it.

Through hard work, innovative thinking, strong end-user engagement and of course a hefty dose of synthetic biology, we embarked on a mission to use synthetic biology to make a difference.

Another big part of our design process was trying to computationally model how our biosensor will behave and helping us understand where are design might lack. Our early conversations made us realise for our biosensor to be better than the current methods , it will have to be easy to use, portable cheap to manufacture and having it paper based was the answer to that.

Prototype 1

Once we decided on to use paper-based biosensor we set out to talk to more people. //link A talk with Susan Deacon made us realise we will need to have multiple tests on one strip, That’s when we found inspiration in the design made by //reference *George Whiteside’s lab for a glucose biosensor*. In this design we would have channels of paper where water will diffuse separated by a hydrophobic material like wax or plastics.

But there was one problem with this design, The distribution of the solution was not uniform #which really created some problems.

Prototype 2

We brainstormed and tried to make our biosensor a bit more simple so that we could have uniform distribution throughout the strip and we came up with this design. This strip would have been of the size of a microscope slide. The Strips you see in centre of the biosensor would again be kept apart by a hydrophobic material and the biosensor would be places inside them.

Although this design meant we could easily predict the diffusion of the liquid as it was all uniform, it did not do well in concentrating the colour produced at one place. It was just too spread out. //Modelling movie

Prototype 3

With the help of our modelling efforts it did not take us long come up with a new solution. Just make some cavities in the design we had that would contain the colour produced.

At this time we really did think we had a winner, but //link talking to more experts made us realise somewhere we could push ourself even more. Reducing the amount of liquid used as the end users might not want to waste a lot of their drug. Although this design only used about 150µl of solution we felt we could do better

Final Biosensor Design

At this time we looked at some our older designs and that when we came up with our current design. This strip only required a tenth of the solution we were using before Uniform distribution, concentrated colours and minimalistic liquid requirements, it has it all.

We were not done yet though, //link A talk with Adam Winstoke gave us the idea that we could increase the ease of use and reliability of results by making a smartphone application and we set out a goal to make that happen

Completing the Device