Scientists are working on a device of just 3mmx4mm with an antenna of 2mm in order to allow better diagnostics in the human bloodstream. Imagine how this sort of technology could revolutionize the science of heart disease, allowing the average person to get a good idea of how much plaque they have in their arteries, etc.
The device is too large to fit in veins for now but the scientists are hoping to shrink the device even more.
Instead of relying on an internal battery the device uses radio frequencies similar to the technology used to activate RFID circuits allowing people access to corporate offices without a physical key or giving them the opportunity to speed through tolls without having to reach into their pockets to get change.
The good news is this is the sort of technology could revolutionize medicine, extend lives, keep us healthy and generate many thousands of jobs if not more. Its conceivable the check-up of the future will rely on many such devices and this seems like a very promising field.