As far as I know this is not an April Fool’s joke. The article is two days old, and the patent does apparently exist.

A company called powercast has developed a way to capture energy from radio waves at a variety of frequencies, and to thereby wirelessly power devices. There is huge potential here for the implantable pacemaker/defibrillator business, as the devices currently have to be (surgically) replaced when the batteries run out. I think the current lifetimes are around 10 years.