This article is part of our new series of Currents, which examines how rapid advances in technology are changing our lives.
Imagine operating a computer by raising your hands in the air like Tony Stark does in “Iron Man”. Or use a smartphone to zoom in on an object, as does the device Harrison Ford’s character uses in Blade Runner. Or a next-generation video meeting where augmented reality glasses enable 3D avatars to be displayed. Or a generation of autonomous vehicles that can drive safely in city traffic.
These advances, and a host of others on the horizon, could be due to metamaterials that allow beams of light to be controlled with the same ease that computer chips control electricity.
The term metamaterials refers to a broad class of manufactured materials made up of structures finer than the wavelength of visible light, radio waves, and other types of electromagnetic radiation. Together, they now give engineers exceptional control in developing new types of ultra-trap sensors, ranging from a telescopic lens to an infrared thermometer.
“We are entering the consumer market for metamaterials,” said Alan Huang, chief technology officer at Terabit Corporation, a Silicon Valley consulting firm who did an early research in optical computing during his 12 years with Bell Labs. “It will go way beyond cameras and projectors and lead to things we don’t expect. It really is a field of dreams. “
The first consumer goods to benefit from inexpensive metamaterials will be smartphones that improve their performance. However, the ability to control light waves in new ways will soon also enable products such as augmented reality glasses that overlay computerized images in the real world.
The technologies themselves are not new. In the early 19th century, the French physicist Augustin-Jean Fresnel proposed the idea of smoothing and brightening optical lenses by using a series of concentric grooves to focus light. A major innovation behind metamaterials is that they are constructed with subcomponents that are smaller than the wavelength of the type of radiation they are designed to manipulate.
For example, to make a lens from metamaterials, cut silicon (which is just glass) thin enough to be transparent and then embed structures in the thin layer of glass that focus light as it passes through.
One of the first to see the commercial potential of metamaterials was Nathan Myhrvold, a physicist who was formerly the head of Microsoft Research.
“When I first got into it, it was quite controversial,” said Myhrvold. “There were scientists who said it was all a bunk.”
Since then, Mr. Myhrvold has founded half a dozen companies based on metamaterial technologies. Some of these companies pursue consumer optical markets, including Lumotive, a Seattle-based company that develops a lidar imaging system with no moving parts.
Lidars use lasers to create precise maps of surrounding objects up to hundreds of meters away. Lidars are widely used by companies developing self-driving vehicles. Today these are mostly mechanical systems that spin a laser beam quickly to create a map.
In contrast, Lumotive uses liquid crystal display technology, originally developed for flat panel displays, to “direct” a beam of laser light. The resulting system is far less expensive than mechanical lidar, so it can be considered for a number of new applications such as delivery drones, self-driving cars and mobile home robots such as smart vacuum cleaners.
With the automotive industry crowded with many lidar manufacturers, Lumotive company representatives have focused their efforts on new markets for home and industrial robots. You haven’t announced any customers yet.
“We’re going in a direction where one of the other attributes we have is the ability to shrink these things to a very small size, which is what makes us unique,” said Bill Colleran, CEO and co-founder of Lumotive.
Another company trying to unlock the potential of metamaterials is Metalenz, which was founded in 2017 by Robert Devlin and Federico Capasso and is currently working on a new method of making optical lenses using powerful and inexpensive technologies to make computer chips.
Many types of metamaterials are made using the same equipment that is used to make computer chips. This is important in that it is a generation of low-cost chips that use light, much like how computer chips could use electricity in the 1960s. This innovation led to a huge new consumer goods industry: electronic watches, followed by video games and personal computers, evolved from the ability to etch circuits onto silicon.
Piggybacking on microchip technology can cost-effectively produce tens of thousands or even millions of two-dimensional lenses that can bend light based on patterns of transparent materials embedded in their surface at a fraction of the cost of today’s optical lenses.
The question these companies need to answer is whether they can offer enough improved performance and lower costs to convince manufacturers to deviate from their current components (in this case, cheap plastic lenses).
An obvious first step for the new technology will be to replace the plastic lenses found in smartphones, which Metalenz will begin with next year. However, this is only the first mass market for metamaterials. Devlin says there will also be applications to control interaction with computers and automotive safety systems, and improve the ability of inexpensive robots to move around in crowded environments.
According to reports, Apple is working on a design for a system that will convert many smartphone functions into thin and lightweight glasses.
“One of the main issues was mass and weight,” said Gary Bradski, chief technologist at OpenCV.ai, a developer of freely available image processing software. “I mean, how much weight can your nose hold?”
The lightness is an advantage of Metalenz, which has demonstrated ultra-thin lenses made of two-dimensional silicon, which are structured with ultra-thin transparent structures, each smaller than the wavelength of the light. However, fabricating the lens like integrated circuits offers other important advantages.
“One of the most powerful things you get from metamaterials, or metasurfaces, is the ability to really reduce the complexity of a system while improving overall performance,” said Devlin. “Medical or scientific applications that were locked up in laboratories because they were really big, bulky, and expensive are now being offered at a price in a form factor that you can fit into anyone’s phone.”
An early possibility will be to make it possible to place sensors directly behind smartphone displays so that the entire surface of a phone can be used. It will also simplify the “structured light” sensors that project patterns of points that are used for facial recognition.
The most powerful characteristic of microelectronics was the ability to miniaturize circuits, making them faster, more powerful, and less expensive over many decades. Similarly, metamaterials will transform the way designers use rays of light.
For example, scientists completing an advanced millimeter telescope due to be installed at Simons Observatory in Chile next year have used metamaterials for the tiles that coat the interior of the telescope to capture virtually all of the stray light. Photons that land on the surface of the tiles are captured by a surface of ultra-small conical structures, said Mark Devlin (unrelated to Metalenz founder), a professor of astronomy and astrophysics at the University of Pennsylvania who leads the design of the telescope.
“The tiles are light, cheap, easy to install,” he said, “and they won’t fall off.”
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