Team:Ionis Paris/Demonstrate

Introduction

As the project ended, our team managed to realize most of its objectives : we are ready to show a functional proof of concept, not only of the biosensor BioBrick, but also of our drone and containment tube. Though some improvements may be brought, such as the guiding system for the drone or the CelloCad optimization for the biosensor, Quantifly is now reay to become a useful tool able to measure pollution in the outside environment. Due to the iGEM Restrictions concerning biological material taken outside the lab, we were not able to actually perform a mapping, but we tried to simulate as best as possible the external conditions.
As it was not a feasible and safe option to spray a cloud of pollutants in the lab and fly through it, for quite obvious reasons, we decided to take a deconstructed approach. We assumed that we would make the elements of our project work one by one in simulated conditions, before putting them all together. We stated that, if the biosensor, the containment tube and the drone are working, the whole project would be functional as well.

Our Biosensor

Our biosensor is the BioBrick we put the most efforts in, in terms of assembly or characterization. Our first bioluminescence results were very promising: it appears that not only the BioBrick device works, but that our statement correlating the intensity of light to the amount of pollutant was correct as well. ! We detailed all the characterization process extensively in the Proof of Concept page, accessible through this link.

The Drone

The design of our drone is detailed in the Hardware section. It is flight-ready, and able to carry our bacteria to the sampling area. Though our drone is only a prototype, it can already carry up to 4 containment tubes, allowing four disctinct samplings. The number of tubes and the sealing mechanisms are the main points we want to improve. However, as you will see at the iGEM Giant Jamboree, our homemade drone is perfectly safe and functional. In case you want to build your own Quantifly drone or to improve our model, you can download all of the 3D models by clicking on this link.

The built drone

The containment tube

The containment tubes were 3D printed and assembled successfully. We were not able to perform any sampling using the tube due to a lack of technical means. However, we managed to mount the tube on our drone, and to create a system allowing the opening and closing of the tube mid-flight. Just as for the drone, the 3D models we used to print our containment tube are available by clicking on this link.

Our tube (Up: disassembled, Middle: sampling, Down: sealed)

Our tube included in the drone chassis

Potential improvements:

In the light of our achievements and realizations, we have thought about a few potential improvements that we could bring to our prototype. As biological improvements were discussed in the Proof of Concept part, we will develop here the mechanical improvements we could bring to our project.
First of all, the use of microfluidics: building a microfluidic circuit directly on our drone would have many advantages: less bacteria would be used with each sampling, which would mean more samples per flight. A smaller amount of substrate would also have to be used per sampling. Our drone might even be able to carry a small photosensitive cell, allowing on-field, real-time measurements.
On a completely different angle, we considered removing bacteria from the drone itself: as we can see on our Human Practices, people do not seem to be ready to use GM-based solutions for now. Removing the bacteria from our drone and replacing them by an air-sampling mechanism would therefore be a solution to this problem, even if the risks of external contamination by ambient air are higher.