
Researchers at Princeton University and the University of Washington have developed an ultracompact camera the size of a coarse grain of salt. The system relies on a technology called a metasurface, which is studded with 1.6 million cylindrical posts and can be produced much like a computer chip.
Image courtesy of the researchers
Micro-sized cameras have great potential to spot problems in the human body and enable sensing for super-small robots, but past approaches captured fuzzy, distorted images with limited fields of view.
Now, researchers at Princeton University and the University of Washington have overcome these obstacles with an ultracompact camera the size of a coarse grain of salt. The new system can produce crisp, full-color images on par with a conventional compound camera lens 500,000 times larger in volume, the researchers reported in a paper published Nov. 29 in Nature Communications.
Enabled by a joint design of the camera’s hardware and computational processing, the system could enable minimally invasive endoscopy with medical robots to diagnose and treat diseases, and improve imaging for other robots with size and weight constraints. Arrays of thousands of such cameras could be used for full-scene sensing, turning surfaces into cameras.
While a traditional camera uses a series of curved glass or plastic lenses to bend light rays into focus, the new optical system relies on a technology called a metasurface, which can be produced much like a computer chip. Just half a millimeter wide, the metasurface is studded with 1.6 million cylindrical posts, each roughly the size of the human immunodeficiency virus (HIV).
Each post has a unique geometry, and functions like an optical antenna. Varying the design of each post is necessary to correctly shape the entire optical wavefront. With the help of machine learning-based algorithms, the posts’ interactions with light combine to produce the highest-quality images and widest field of view for a full-color metasurface camera developed to date.

Previous micro-sized cameras (left) captured fuzzy, distorted images with limited fields of view. A new system called neural nano-optics (right) can produce crisp, full-color images on par with a conventional compound camera lens. Image courtesy of the researchers
A key innovation in the camera’s creation was the integrated design of the optical surface and the signal processing algorithms that produce the image. This boosted the camera’s performance in natural light conditions, in contrast to previous metasurface cameras that required the pure laser light of a laboratory or other ideal conditions to produce high-quality images, said Felix Heide, the study’s senior author and an assistant professor of computer science at Princeton.
The researchers compared images produced with their system to the results of previous metasurface cameras, as well as images captured by a conventional compound optic that uses a series of six refractive lenses. Aside from a bit of blurring at the edges of the frame, the nano-sized camera’s images were comparable to those of the traditional lens setup, which is more than 500,000 times larger in volume.
Other ultracompact metasurface lenses have suffered from major image distortions, small fields of view, and limited ability to capture the full spectrum of visible light — referred to as RGB imaging because it combines red, green and blue to produce different hues.
“It’s been a challenge to design and configure these little nano-structures to do what you want,” said Ethan Tseng, a computer science Ph.D. student at Princeton who co-led the study. “For this specific task of capturing large field of view RGB images, it was previously unclear how to co-design the millions of nano-structures together with post-processing algorithms.”
Co-lead author Shane Colburn tackled this challenge by creating a computational simulator to automate testing of different nano-antenna configurations. Because of the number of antennas and the complexity of their interactions with light, this type of simulation can use “massive amounts of memory and time,” said Colburn. He developed a model to efficiently approximate the metasurfaces’ image production capabilities with sufficient accuracy.
Colburn conducted the work as a Ph.D. student at the University of Washington Department of Electrical & Computer Engineering (UW ECE), where he is now an affiliate assistant professor. He also directs system design at Tunoptix, a Seattle-based company that is commercializing metasurface imaging technologies. Tunoptix was cofounded by Colburn’s graduate adviser Arka Majumdar, an associate professor at the University of Washington in the ECE and physics departments and a coauthor of the study.
Coauthor James Whitehead, a Ph.D. student at UW ECE, fabricated the metasurfaces, which are based on silicon nitride, a glass-like material that is compatible with standard semiconductor manufacturing methods used for computer chips — meaning that a given metasurface design could be easily mass-produced at lower cost than the lenses in conventional cameras.
“Although the approach to optical design is not new, this is the first system that uses a surface optical technology in the front end and neural-based processing in the back,” said Joseph Mait, a consultant at Mait-Optik and a former senior researcher and chief scientist at the U.S. Army Research Laboratory.
“The significance of the published work is completing the Herculean task to jointly design the size, shape and location of the metasurface’s million features and the parameters of the post-detection processing to achieve the desired imaging performance,” added Mait, who was not involved in the study.
Heide and his colleagues are now working to add more computational abilities to the camera itself. Beyond optimizing image quality, they would like to add capabilities for object detection and other sensing modalities relevant for medicine and robotics.
Heide also envisions using ultracompact imagers to create “surfaces as sensors.” “We could turn individual surfaces into cameras that have ultra-high resolution, so you wouldn’t need three cameras on the back of your phone anymore, but the whole back of your phone would become one giant camera. We can think of completely different ways to build devices in the future,” he said.
Original Article: Researchers shrink camera to the size of a salt grain
More from: Princeton University | University of Washington
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Metasurface imaging
- Global Hyperspectral Imaging Systems Market Report 2022 to 2027: Industry Trends, Share, Size, Growth, Opportunities and Forecasts
DUBLIN, Jan. 27, 2023 /PRNewswire/ -- The "Hyperspectral Imaging Systems Market: Global Industry Trends, Share, Size, Growth, Opportunity and Forecast 2022-2027" report has been added to ...
- New methods to improve super-resolution imaging techniques give a sharper view inside cells
New methods to improve super-resolution imaging techniques are giving biologists a clearer and more complete view of the inner workings of living cells. A new paper in Nature Biotechnology from ...
- EU initiative aims to link up cancer imaging across the continent
The European Cancer Imaging Initiative aims to bring various datasets together, to make it easier for hospitals and researchers to access high-quality data. A new EU initiative has launched to ...
- A Princeton lab has designed a new antenna that works 'like a transformer robot'
The shape-shifting antenna array can be reconfigured by folding and unfolding the panels to assume shapes like curves, saddles and spheres.
- Wearable sensor uses ultrasound to provide cardiac imaging on the go
"The technology enables anybody to use ultrasound imaging on the go," Xu said. Thanks to custom AI algorithms, the device is capable of measuring how much blood the heart is pumping. This is ...
Go deeper with Google Headlines on:
Metasurface imaging
[google_news title=”” keyword=”metasurface imaging” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
Nano-sized camera
- Lululemon's viral belt bag is always sold out — but these 9 bags are just as good
Whether you've bought it or not — there's no denying Lululemon's Everywhere Belt Bag has likely infiltrated your social media feeds and morning dog walks. Despite releasing various versions of the ...
- miniature camera
For those working in the N scale, there’s now an easy way of observing your project as the train driver would see it: [Vassily98] managed to squeeze a wireless camera into an N-scale railcar.
- Nespresso Vertuo Next espresso machines are 25% off on Amazon right now
Nespresso makes some of the most popular espresso machines on the market, and right now you can score a great deal on one of the brand's top-rated models. The Nespresso Vertuo Next espresso maker is ...
- Orbbec Debuts Femto Mega at CES 2023, the Industry's Highest Resolution 3D Vision Camera with Integrated Depth and AI Processing
The 1 mega-pixel depth camera is complemented by a high performance 4K resolution RGB camera with 90 degrees' FOV. A built-in Nvidia Jetson Nano is used to run advanced ... our current system while ...
- Amazon just put the new Amazon Fire HD 8 tablet on sale for an unbeatable price
Shop the top deals this week at Amazon, including savings on Apple AirPods, iRobot Roombas, coffee makers and more.
Go deeper with Google Headlines on:
Nano-sized camera
[google_news title=”” keyword=”nano-sized camera” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]