~ Project development.
~ post date: 2017.7.9, recent update: 2017.7.9

The following is a review of my final work, Pure Imagination.

My presentation to the Fab Academy was June 19 and the deadline for polishing the project was June 28. I am finished.

All the tasks have been completed.

I have no remaining tasks. All the tasks have been completed.

Regarding the science : The microbial fuel cells are generating electricity as is evidenced by a voltmeter and the volt sensing electronics/ program I fabricated. However, I still have much to learn in terms of environmental influencers, plant type differences, cathode/ anode material strategies, influencing the number of electrogenic microbial organisms, current output and stability, and cost control vis a vis electrical output. That said, I am a little more than two weeks into actively working with this science, and far removed from any biology or chemistry schooling and I feel excited to continue with this work after Fab Academy.

Regarding the grow module : Changing to the concrete cells made the project more robust at the cost of a significant amount of time. I think laser cutting 9 cells would have taken two hours based on the experience of making one. Cutting the foam, waiting for the oomoo to cure, and casting the concrete (many many broken shells in finding the right formula) used easily over 100 hours to get 9 modules. When the cement is wet, water will slowly drip through the walls so it did not completely solve that issue with the laser cut modules. Granted, pouring cement is simple, when the formula is known. Further, the mold had issues beyond the oomoo averted disaster, there was significant flex which fortunately could be made up for in the frame. The walls are not straight. I do not mind it for this prototype because it has a nice quality but in demand of greater precision, I will have to reinforce the mold more and do better with the oomoo casting.

Regarding the frame : The frame slots together, the joints are hidden, the LCD module fits and the grow modules are supported in place. However, working within the constraints of the Fablab O CNC mill setup was a difficult experience. I would have liked to further develop the frame and explore other materials but even the smallest test would require upwards of a day on the machine. Also, I do not like how the wood hides all the electronics. Normally, hiding the electronics is desirable in projects. For something of this nature, I think seeing the electronic connections is part of the magic.

Regarding the electronics : The electricity monitoring and data logging with an ATtiny44 works when connected to a computer (data logging through Processing), or simply to an LCD when connected by battery. I need more data sensing to get a clearer picture of what is happening within the grow modules. I could have chosen to not use the LCD, freeing several pins for data sensing, or used a controller with more pins, for instance.

As for the planned build, all the tasks have been completed.

Frankly, this is a huge question for me that would require a terrifyingly verbose answer. In the general sense, what I have learned has been thoroughly documented throughout the pages and months of this fab blog. Specific to Pure Imagination, I have learned that generating electricity with the aid of plants is possible by even a scientifically uneducated person as myself, wonderful, and an exciting frontier. There is a lot of development between now and replacing fossil fuels so I hope more people get involved. And, back to the general, I gained the confidence that I can truly make almost anything with access to the tools common to fab labs and, most critically, with the help of all the people who develop their own projects, thoroughly document their progress and share online. Thank you.