BottleVoltaic is an attempt at a kind of modular photobiochemical device using recycled materials to build an algal photo-microbial fuel cell. The algae is grown in a used PET bottle and the anode is made up of cut-up aluminium cans. The cathode is an old trusted sheet of platinum on carbon, the same as was used in Moss FM.
The lid contains all the “tech”, so to speak, and could therefore be attached to any PET bottle with the same neck diameter.
An article with information on how the device is built was published in April this year in the journal Biology.