Wireless power delivery has been on the research agenda for well over a century and the first patent was issued in 1894 in the wake of experiments conducted in the early 1890s by Serbian-born Nikola Tesla, in whose eminent memory the famous electric car company was named. His work led quickly to successful demonstration of power transfer via near field inductive or capacitive coupling, now well established in various commercial systems from induction hobs for cooking to mobile phone charging cradles, as well as medical implants such as artificial cardiac pacemakers. But the dream of eliminating power cables can only be achieved through far field transmission of electricity, and that has proved much more elusive. Now it turns out that…