Hardware Model

Biofrag Design

The Biofrag design took inspiration from Bioballs currently used to clean fish tanks. The initial idea was to make the system as porous as possible. The first iterations looked at a biodegradable design which included PLA, Woodflex, and PVA. The challenges the team faced when designing and implementing the Biofrag included the likes of its 3D design.

The Biofrag went through two physical alterations. However, prior to designing even the first Biofrag, the 3D structure was theoretically changed 3/4 times before the team was happy to proceed. This was due to the fact that we wanted to optimize the conditions for plant growth whilst also maintaining structural integrity and ensuring that the enzymes and agar for which the Biofrag would contain would remain inside thus ensuring biosafety.

Biofrag v1

Biofrag v1 the theoretical iteration looked at designing a single 3D spherical structure that was porous. The sole purpose of this structure was to harbor the bacteria E. coli BL21 which would act as the chassis for producing chlorite dismutase and perchlorate reductase which would act in tandem with each other to help remediate the surrounding soil. The issue we found with this delivery is the single Biofrag design lacked safeguards to ensure biosafety was adhered to.

Biofrag v2

The second theoretical iteration improved upon version 1 by adding an internal small Biofrag to the preexisting larger Biofrag, this provided greater biosafety and provided the team with a second outside layer to add possible technology such as sensors. This interaction was later 3D printed, both the inner and out layers can be seen below in figure 1 and figure 2.

Figure 1. The outer layer of Biofrag

Figure 2. The inner layer of Biofrag

From figure 1 and figure 2 the inner and outer layer is seen to be porous however on either pole of the two half-spheres (which would later be screwed into duplicate versions of themselves) there were no holes. Biofrag v3 improved upon this idea.

Biofrag v3

The issue with the initial versions of the Biofrag is that the team enzymes, perchlorate reductase and chlorite dismutase, had no means of transportation out into the surrounding soil. Thus the team looked at putting a vegetative seed in the inner sphere. This would not only help transport the enzymes out into the surrounding soil through its adherence to the roots and plant, it would also act as a dual purpose component, growing vegetables (food) for those that colonize Mars whilst also bioremediating the soil. With the addition of the seed, the enclosed nature of the poles on the inner and outer spheres of the Biofrag needed to be redesigned. Biofrag v3 was designed around the premise that we needed a larger opening for the plant itself to grow out of. Figure 3 and figure 4 illustrate the innovative improvements that ensued.

Figure 3. Outer layer v3 (open top and bottom poles)

Figure 4. The inner layer (open top and bottom poles)

Figure 5. Illustration of final Biofrag design.

Figure 5 above illustrates the final form of the Biofrag mechanism, within these two 3D spherical structures, the seed for the selected plant, the enzymes chlorite dismutase, and perchlorate reductase would all be encapsulated, the seed(s) would be within the inner Biofrag, the newly designed open polar ends would allow for better and easier plant growth. The porous surface throughout the surface of both the inner Biofrag and outer Biofrag would allow for the secretion of the enzymes, whilst also allowing for plant roots to grow and facilitate the transport of the enzymes out into the greater surrounding environment. Thus improving upon initial ideas developed which lacked a mechanism for transport of the enzymes into the surrounding environment. The dual spherical innovation allowed for greater contents control and the screw design allowed for ease of use for the user.

Biofrag Isolation Unit

The Biofrag Isolation Unit will act as a means of transport for the Biofrags on their way to Mars. The purpose of the BIUs once on Mars will act as a simplistic means of soil analysis and testing. The top of the box will be made clear to allow scientists and operators to view the plant growth easily. Figure 6 below shows a 3D render of the BIU and the ports for the oxygen and chlorite sensors that will be used to test for the by-products of the bioremediation process.

Figure 6. Depiction of the Biofrag Isolation Unit.