The Head Up Displaywas invented for the military during World War II, projecting imagery on to the cockpit canopy so the pilot did not have to look down at his instruments. These days HUDs are standard in all sorts of aircraft and cars, and there are even swimming goggles which will display a lap counter for you. Researchers at the University of Washington are inching closer to the next step: contact lenses as display devices.
As National Defense magazine reports, the difficult part is integrating the electronics with the lens. The process for dealing with this sounds like magic: the device assembles itself. Although they look like a fine white powder, each of the individual components – sensors, antennae, semiconductor circuits and LEDs – is a particular shape. They are floated over the polymer substrate, which is etched with tiny holes corresponding to the shape of each component. The components fall into place like pieces of a jigsaw puzzle, and are then locked into position.
Bringing batteries into this assembly line would be tough. So the contact lenses are powered remotely by a beam of radio waves. The energy level is only on a scale of microwatts, but for safety reasons they have not yet been tested by a human subject -- that's why the picture above rather incongruously shows a rabbit wearing the high-tech lens.
If they can ever get humans to wear the lenses, though, there may be some distinct military advantages.
It'll allow troops to wear sunglasses, protective goggles, or a night-vision device while still getting HUD-style info. The lenses might also act as a sensor, providing a non-invasive way of continually monitoring and displaying blood glucose and other health factors.
At an Institute for Defense and Government Advancement conference, University of Washington engineering professor Babak Amir Parviz (we've covered his work before) showed how a grid of red LEDs just 25 microns could display text. For now, it's just a fuzzy single letter "F." Later on, he hopes to increase the pixel count to produce clearer images, and also to introduce color. That would open up a whole new range of possibilities. One suggestion is that the lenses could be used for immersive gaming, creating a whole virtual reality around the wearer. It would provide a simple way of receiving text messages unobtrusively, like a visual version of those radio earpieces worn by Secret Service agents. Or it could act as a SatNav system which would guide you without having to take your eyes off the track ahead.
But there would also be some applications specific to the military. It might be useful to have images from a gun-camera like the Smartsightbeamed direct to a contact lens, so you can shoot around corners without exposing your face. Or it could display imagery from an Eyeball or other tactical robot going into buildings ahead of troops.
As with the original military aircraft HUD, it would be valuable in any situation where the user needs to keep looking ahead rather than glancing down. However, when this sort of expensive electronics is involved, losing a contact lens might be more than a minor inconvenience.
Image: University of Washington*