When using radio spectrum to transmit signals from one device to another we have to code them in a specific way at a specific frequency so that the signal can be recognised. Each way of coding (we call them Bluetooth, Zig Bee, WiFi) has its own plus and minus. Sometimes what is best for a device it is not for another.
Researchers at Washington University have demonstrated a way to convert "on the fly" one way of transmission into another, say receiving a Bluetooth signal and sending back a WiFi signal. They called it "interscatter", a merge of Inter-technology for backscatter. The interesting part is that the conversion is made using as energy source the one that is carrying the received signal reflecting it, in the new transmission system. In this way the energy requirement gets very small, the researchers say tens of micro-watts, thousands of times less than WiFi system.
As proof of concept they developed one contact lens equipped with an antenna that receives Bluetooth signals from a smart watch and sends back a WiFi signal to a smart phone.
This would enable WiFi transmission from sensors embedded in the brain to control seizures or monitor Alzheimer, as example. Other applications are foreseen in contact less cards communications.
This is a pretty good result for its application in the area of Internet of Things where the energy budget is often severely limited.