It is often said that innovation occurs at the intersection of seemingly unrelated ideas. As an example, consider urine and origami.
A recent paper in the Journal of Materials Chemistry A titled “Urine-Activated Origami Microbial Fuel Cells to Signal Proof of Life” by researchers at UWE Bristol has the details. The problem statement would seem to involve a portable, lightweight emergency signaling device that never suffers from dead batteries. The use of microbial fuel cells to generate power from human waste is not entirely new, but the expense of the components, combined with the environmentally damaging end-of-life disposables, have been stumbling blocks.
Dr. Jonathan Winfield and his team solved the problem with origami-like pyramids of recycled paper coated with specially engineered layers. One of these layers is made up of tiny bio-generators that spring to life and generate electricity when doused in pee. In the featured application, this electricity would power an emergency locator beacon which could be used by hikers in distress.
If you are both lost and dehydrated, you are out of luck.