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Smartphone-Enabled Replicators Are 3-5 Years Away, Caltech Professor Says

A new imager will allow iPhone wielders to snap a picture of just about anything, and 3D-print a super-accurate replica within minutes, Caltech says.
April 6, 2015, 3:05pm
Printing an iPhone case on the Maker Replicator. Screenshot: YouTube

In just a few years, we could see the mass proliferation of smartphone-enabled replicators. At least, Caltech electrical engineering professor Ali Hajimiri and his team of researchers thinks so. They've developed a very tiny, very powerful 3D imager that can easily fit in a mobile device, successfully tested its prowess, and published the high-res results in the journal Optics.

Hajimiri claims the imager may soon allow consumers to snap a photo of just about anything, and then, with a good enough 3D printer, use it to create a real-life replica "accurate to within microns of the original object."


It's called the nanophotonic coherent imager (NCI), and it's small—it spans just a single square millimeter, and therefore easy to integrate into a smartphone—and cheap, since it's made out of silicon, like most sensors. It is also exceedingly accurate, Hajimiri says—it utilizes LIDAR, a remote detection and sensing technique that bathes the intended object in lasers.

"In the NCI, the object is illuminated with this coherent light," Caltech's announcement explains. "The light that is reflected off of the object is then picked up by on-chip detectors, called grating couplers, that serve as 'pixels,' as the light detected from each coupler represents one pixel on the 3D image."

Hamiri tells me he sees the technology moving to mass market in three to five years.

There have been previous stabs at smartphone 3D imaging, but the NCI, Hajimiri says, will improve upon that resolution by up to 1,000 times. "They measured their pixels in millimeters. We measure in microns," he said. Hajimiri sent me a scan of a penny the NCI had created. "You can read the writing and the year," he said. "You can see 'liberty' and 'under God.'"

There's a strict limit on what consumers could be able to print, of course, imposed by the quality of the fabricator available and the materials at hand. But 3D printer (and Star Trek) enthusiasts will no doubt be enthused by the prospect—hell, one of Makerbot's popular product lines is called ​the Replicator.


The way Hajimiri sees it, the NCI promises commercial, industrial, and even transportation applications. He emphasizes that he believes it could become commonplace on smartphones, allowing users to carry out ultra-precise scans and print out replications at home.

"The next step is to transition to a commercial product that you can put on your phone," Hajimiri said. "It will give you very fine replications. If you have a machine part or a gear, you can copy that."

The premise isn't really far-fetched. The 3D printing market continues to boom: Worldwide, the industry grew 34 percent last year, reaping $3.3 billion in revenues. Some 133,000 3D printers were shipped in 2014, which is 68 percent more than were moved in 2013. As the printers proliferate, so will the software and apps that will let their owners experiment with them.

It makes Caltech's statement announcing the breakthrough seem all the more plausible: "Imagine that you can just pull your smartphone out of your pocket, take a snapshot with its integrated 3D imager, send it to your 3D printer, and within minutes you have reproduced a replica." If Hajimari is right, that world is just a few years away.

"Any system that requires accuracy" would find the device a boon, Hajimari said. And it could prove useful in autonomous vehicles and robotics. "It would give them precise information about movement," he said.

"Each pixel on the chip is an independent interferometer—an instrument that uses the interference of light waves to make precise measurements—which detects the phase and frequency of the signal in addition to the intensity," Hajimiri said. Unlike with standard cameras, each pixel in the NCI's images provide information about both intensity and distance.


The NCI could likely be cheaply manufactured at existing plants already turning out silicon chips for the tech industry. "It's the same technology that's been used in silicon chips for years," Hajimari said.

Image: ​Star Trek screenshot

There's a reason that particular Star Trek tech has been lodged in our cultural consciousness for decades—the prospect of rapidly fabricated objects, emerging seemingly from thin air, is an enduring and powerful one. Thanks to the fruits of Moore's law and the surging maker's movement, we may be able to at least emulate that process.

Even if the NCI becomes ubiquitous, the smartphone-enabled replicator itself will probably in the end be a fairly niche product—powered by a slick app, no doubt— embraced mostly by makers and gearheads. Who's really going to want or need to copy their household stuff or machine parts on a regular basis, for the time being?

But with its host of other potential applications, the nanophotonic coherent imager may indeed worm its way into our devices. And the age of the DIY replicator will have quietly and unassumingly been ushered in.