There’s no ignoring the prism-like display on the current version of Google Glass. It juts out from the frame and sits just above your eyeball. When the display is on, other people can’t fail to see the bright little mirror image of what you’re looking at. Even when the display is turned off, rendering the prism a clear block in front of your right eye, it’s impossible to forget about. For a device like this to have a chance, it will need a display that is much more discreet.
One solution may be something like what’s in the works at Lumiode, a startup that uses LEDs to create microdisplays. Typically, LEDs serve as the light source at the rear of a display, and the light passes through filters to form the pixels that together create images. Lumiode eschews the filters. Instead, it uses individual LEDs as pixels by adding a layer of transistors to control how they emit light. Lumiode founder and CEO Vincent Lee says the technology could yield tiny displays that are 10 times brighter and more energy-efficient than other display technologies. That could make it easier to integrate a display into regular-looking glasses, cut down on clunky batteries, and make the glasses work better outdoors, too.
Lumiode is now focused on perfecting the process of fabricating the layer of transistors atop the LEDs without ruining the lights. Lee says the obtrusiveness of a Lumiode display that’s built into a pair of smart glasses will depend on a few factors, including the optics used in the glasses. Eventually, he says, it could fit into the frame.
A more radical approach to cutting down on smart glasses’ bulk may be to simply take the lens needed to magnify what’s on the display out of the glasses and bring it closer to the eye. A company called Innovega is doing this by developing contact lenses with a tiny bump that serves as a microscope for content that can be streamed from the inside of a pair of glasses. The lenses do nothing when you’re looking at the world around you, but when media is streamed toward your eyes from a projector or display panels built into glasses, it passes through the bump on each contact and comes into focus just in front of the eye. This offers the benefit of showing content to both eyes—and it can stay in focus as you move them.
Though it remains awkward, Glass is already miles from where it was in 2011, when it was like a scuba mask with a phone and cables attached to it.
Innovega showed off an early prototype of its technology, streaming high–definition content, at the 2014 International Consumer Electronics Show in Las Vegas. The glasses looked a lot like normal—albeit dorky—sunglasses, and chief executive Steve Willey says the company is developing a consumer contact lens. It plans to seek approval from the U.S. Food and Drug Administration in 2015.
Even if displays can be made practically invisible and much more energy-efficient, smart glasses will need battery technologies that can hold up to a full day of usage and eliminate the bulging batteries currently connected to Glass.
That probably will require a combination of breakthroughs. Software must be optimized to use power more frugally (already, the Glass team has made progress in this regard). And something like the thin, flexible, printed rechargeable batteries made by the startup Imprint Energy could be contained in the frames. These zinc-based batteries would eliminate some of the bulk typically associated with lithium-ion batteries, which require protective layers because they are sensitive to oxygen.
In addition, some sort of power harvesting could replenish the batteries throughout the day. A company called Perpetua Power is working on technology that uses body heat to produce electricity; in theory, your smart glasses could extend their battery life with tiny thermoelectric generators on places that touch your skin, such as the bridge or temple. For now, though, Perpetua’s module is much too big: one by two centimeters. And each one can generate only a bit of the power you’d need to run even a fitness-tracking wristband. Perpetua’s bracelet-like prototypes include eight to 10 modules.