EEG Controlled Blimp (Thought Bubble)
Schematic sketch for the blimp
After many failed attempts we finally succeeded in fusing the silver mylar material that we will make our blimp with. Trying the methods seen online which made sense, like thermally fusing the material, but proved unreliable… always springing leaks. Mylar is a polyester film (Biaxially-oriented polyethylene terephthalate to be exact)… and very few things stick to it. It is a fairly chemically resistant material… holding up against acetone even for quite some time.
We tried various combinations of heat, degreasing with solvent and then heat which helped to some degree, but it was by chance that we found a really effective method:
Methyl Ethyl Ketone… also known as MEK is among the few things that effectively fuses the polyester film chemically, creating a seam that remains flexible after it has cured. We can’t stress enough how much it smells… yet it is not regarded as an extremely toxic chemical to our surprise, but does happen to be on a list of Precursors and Chemicals Frequently Used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances Under International Control.
Although using pure MEK does work, it is very difficult to control due to its extremely fast rate of evaporation. Instead we found an MEK-based adhesive with a more viscous consistency to work best:
Loctite brand vinyl plastic and fabric adhesive
Seen below is a test balloon that has successfully held air for more than a day:
Mylar balloon
Detail of the chemically fused seam
To our surprise the seem resembles the heat fused seams almost exactly but are many times stronger. When testing the seam’s strength the film usually tears at the edge of the seam rather than the seam actually failing.
EEG
Mind Flex interactive EEG based toy
While we had hoped to build our own EEG circuit we ended up working with the popular “mind flex” toy; elaborating on work already done by Eric Mika and Arturo Vidich. While the resolution of the Mind Flex is very low (one electrode only), it is proven and consistent with the huge help of Eric’s Arduino-Brain library.
While we have been able to get steady readings that show apparent “Attentive” and “Meditative states it is not without a good deal of noise as always. Getting the blimp to float is a significant challenge though getting useful readings from this EEG setup will be just as hard.
Below is some of our initial EEG readings graphed:
EEG Testing
Control
UI (Urinary Interface)
Making some headway with the fluid sensor array. We were able to re-purpose an old PS2 keyboard along with an existing Arduino library as a sensor array. We will use each key sensor pad and rewire them to our fluid sensor array. We can then determine the general location of a fluid stream.
Making a prototype array:
