Difference between revisions of "Team:Grenoble-Alpes/Hardware"

What if your Cell phone became a portable lab.

What if you could use your cell phone as a laboratory ? It might sound weird and difficult, but using 3D printing technique, basic electronics components and programming, your phone may become a very efficient tool. This is what we aimed to do with SnapLab, our portable kit that detects cholerae. SnapLab is the combination of a user-friendly application (lien page app) with a 3D printed device, in which smartly designed plasmids are used to detect particular DNA sequences (lien part bio).

SnapLab is the result of the collaboration between biology and engineering students. We designed an all-in-one kit, which integrates own-made lab instruments. Not only a measurement tool, SnapLab is also able to complete the entire analysis. After extracting the DNA sequence of interest from feces, the plasmid that we designed hybridizes with this particular DNA sequence. The plasmid is then internalised by the bacteria through a process of bacterial transformation, that once again occurs within the kit. Thus, bacteria are able to emit fluorescence that the smartphone captures by taking a photograph. All these steps are made possible by the 3D printed kit and the Arduino card connected to the smartphone.

SnapLab has entirely been created in 3D with Onshape, a full-cloud and public online software. All 3D models are available for those who have a free account on Onshape. Use the keyword “SnapLab” with the research tool. All parts are given in the following table. Weight, time of printing and the approximate price of the material are pointed out.

Our project is part of the Do It Yourself (DIY) approach. It is to say that the kit is designed to be easily editable and reproduced. To do so, we decided to use 3D printing as much as we could. It has two major advantages. First, 3D printing allows to create parts with very specific dimensions, thus minimizing the number of parts as to favor a better insulation between the different compartments. Second, mechanical properties of the material used in 3D printing, Acrylonitrile butadiene styrene (ABS), are interesting to ensure the solidity of the structure.

Moreover, ABS is also heat resistant. SnapLab needs temperature from 0°C up to 75°C and ABS reaches its transition state at 125°C, so this is the perfect material in every aspects. We are also aware of the potential danger that represent genetically modified bacteria, especially if there are any kinds of leak. The impermeability of the device is ensured by the parameters of the 3D printing, using a shell thickness of 3mm.