Recent miniaturization of electronic components not only bring smaller projects but also less power hungry ones. We now have pocket computers that do in seconds what room-sized computers do in a day — powered by batteries to boot.
I read an article at New Scientist about the recent development of a fuel cell that is only 3mm by 3mm by 1mm. Although it’s still being developed heavily, they’ve manage to make a cell that can produce 0.7 volts at 0.1 milliamp for 30 hours. Not yet mainstream for our ordinary gadgets like the mobile phone but once it gets done, we’ll definitely be seeing environment friendly energy sources that also makes our gadgets have longer lasting “juice”.