Feeling smug about those brand-name cans you just bought? A pair of researchers from Berkeley just made 'em obsolete with some Graphene. Conventional gear needs an oscillator that has to be damped down to produce a constant sound between 20Hz and 20kHz. Graphene, on the other hand, can be tailored to do the same job without any complicated, and power draining, over-engineering. Qin Zhou and Alex Zettl found their power-sipping setup to be as good, if not better than the pair