Two articles on batteries, or the lack thereof. While they are targeted for military use where soldiers often have to carry up to 10kg in batteries for power needs, they will likely be commercialized for civilian use:
- US Army researchers are designing more powerful, slimmer, lighter batteries–up to 30% more power when the norm of increase is about 1%, and a single cell powering up to five volts. Army researchers are also investigating ‘ubiquitous energy’ — using indigenous sources such as water. Energize! (Armed with Science)
- UK researchers from Cranfield University, The University of Liverpool and University of Salford have designed an energy harvester which, when fitted to the outside of the knee joint, in normal motion could do away with batteries altogether. Current state is two milliwatts of power but with some improvement is projected to generate 30 milliwatts. The pizzicato knee-joint energy harvester: ECN magazine article, direct link to IOP Science for paper.