In order to demonstrate our project into real-world conditions, we developed a custom drone able to safely transport our organisms into the chosen areas. We used a 3D printer at La Paillasse to print most of the drone parts ourselves (chassis and feet). The files used to print the drone are available here. The drone was designed in order to safely contain genetically modified organisms using a tube that we also designed and printed. The tube, working as an airlock, allowed air sampling without risking bacterial dissemination in the external environment. (Please note that containment tests have only been conducted inside the lab).

The drone is a quadricopter with a 980kv power. It has 4 ESC (motor speed control systems) of 30A and is equipped with a flight control system as well as a distribution circuit. It runs on a 3S battery (5Ah).
We designed it to hold four tubes in the prototype version. In order to open those tubes, the drone is equipped with servomotors able to lift the lid of the tubes. The drone has a 500g payload capacity which is more than needed and a theoretical autonomy of 8 minutes. The extra payload will be used to add other modules to the drone (such as a bleach bottle as explained below).

Even if this drone is just a prototype, it is the first step towards field applications of our project. Our main objective was to realize a flying drone able to carry the bacteria on-site without dissemination and to sample external air. We did reach this objective: see our drone flying.

There is already a very simple safety mechanism on the drone. If it goes out of the controller’s range, it will land. However, this will not avoid bacterial dissemination if the drone crashed. This is why a second safety mechanism had to be set up.
Our solution to this problem is a small bottle of bleach attached under the drone. In the event of a crash, the bottle would break and spill the bleach, killing any bacteria that might have leaked out of a broken tube.
We proposed some improvements to this prototype:

Containment tubes

Tube design and materials

The bacteria containing tube was one of our challenges. As we are working with living modified organisms, it had to be perfectly closed to avoid any dissemination. Therefore, we designed a tube able to sample external air and expose bacteria to it while remaining perfectly hermetic.

The tube functions as an airlock. There is a compartment between the outside environment and the inside of the tube that acts as an interface that does not directly allow the contact of the tube's outside with the tube's inside. At the beginning the tube is half open but the air cannot enter. Thanks to little servomotors placed on the drone, tubes can be opened to sample the air. However, at this step, the bottom of the lid still closes the tube preventing bacterial dissemination. Finally, the tube closes fully and the air goes though the interface into the inner part of the tube in which bacteria are. Exposed to the pollutant, the bacteria will start producing luciferase.

We believe that the tube we designed can be a very useful tool for applied synthetic biology and future team will do their best to improve it within the iGEM competition.

Air sampling by the containment tube without bacterial dissemination