We think of hacking as bending technology to our will. But some systems are biological, and we’re also starting to see more hacking in that area. This should excite science fiction fans used to with reading about cultures that work with biological tech, so maybe we’ll get there in the real world too. Hacking farm crops and animals goes back centuries, although we are definitely getting better at it. A case in point: scientists have found a way to make photosynthesis better and this should lead to more productive crops.
We learned in school that plants use carbon dioxide and sunlight to create energy and produce oxygen. But no one explained to us exactly how that happened. It seems a protein called rubisco is what causes this to happen, but unfortunately it isn’t very picky. In addition to converting carbon (from carbon dioxide) into sugar, it also converts oxygen into toxic compounds called ROS (reactive oxygen species) that most plants then have to spend energy eliminating. Scientists estimate that if you could recover the calories lost in this process, you could feed an additional 200 million people worldwide at current production levels.
Battery cells work by chemical reactions, and the fascinating Hybrid Microbial Fuel Cell design by [Josh Starnes] is no different. True, batteries don’t normally contain life, but the process coughs up useful electrons all the same; 1.7 V per cell in [Josh]’s design, to be precise. His proof of concept consists of eight cells in parallel, enough to give his cell phone a charge via a DC-DC boost converter. He says it’s not known how long this can be expected to last before the voltage drops to an unusable level, but it works!
There are two complementary sides to each cell in [Josh]’s design. On the cathode side are phytoplankton; green micro algae that absorb carbon dioxide and sunlight. On the anode side are bacteria that break organic material (like food waste) into nitrates, and expel carbon dioxide. Version 2 of the design will incorporate a semi-permeable membrane between the cells that would allow oxygen and carbon dioxide to be exchanged while keeping the populations of micro-organisms separate; this would make the biological processes more complementary.
A battery consisting of 24 cells and a plumbing system to cycle and care for the algae and bacteria is the ultimate goal, and we hope [Josh] can get closer to that now that his project won a $1000 cash prize as one of the twenty finalists in the Power Harvesting Challenge portion of the Hackaday Prize. (Next up is the Human Computer Interface Challenge, just so you know.)
[Daniel Nocera], working with the MIT Energy Initiative, has come up with a method to easily and cheaply store energy generated from solar electricity with water. The method uses two catalysts of non-toxic and abundant metals to separate the water into both oxygen and hydrogen. These gases are then stored, and later recombined in a fuel cell to generate power. The process was inspired by photosynthesis, and helps to make sources such as solar power viable around the clock. Current storage technologies are both expensive and inefficient, so technologies like solar are only useful when the source is available. This will allow homes to cheaply and easily store power generated through solar and other technologies. While this is only part of the solution towards the current energy problem, it could go a long way towards decreasing our use of non-renewable sources. When combined with other new breakthroughs in the field, you can easily imagine more homes coming off the grid. Check out the short video after the break.