Scientists Build a Camera That Can Track Invisible Particles in 3D – A Breakthrough That Could Transform Physics and Medicine

Imagine a camera so powerful that it can "see" the invisible paths of tiny particles moving through matter. It sounds like science fiction, but scientists have now developed a revolutionary technology that can do exactly that.

Researchers from ETH Zurich and EPFL Switzerland have created a new particle detector called PLATON. Instead of using millions of tiny detector pieces like current systems, PLATON uses a single block of special light-producing material, a highly advanced light-field camera, ultra-sensitive photon sensors, and artificial intelligence (AI) to create detailed 3D images of invisible particle tracks.

This breakthrough could make future particle detectors cheaper, simpler, and even more powerful. It may also improve medical imaging technologies such as PET scans.

Why Are Invisible Particles So Hard to Detect?

Our universe is filled with particles that are almost impossible to see.

Some of them, like neutrinos, pass through planets, buildings, and even our bodies every second without leaving much of a trace. Scientists also believe mysterious dark matter particles may exist, but detecting them has been one of the biggest challenges in modern physics.

To study these particles, researchers build enormous detectors that wait for the rare moment when one of these invisible particles interacts with ordinary matter.

The bigger and more detailed the detector, the better the chances of catching these extremely rare events.

How Today's Particle Detectors Work

Most modern particle detectors use a material called a scintillator.

When a charged particle passes through this material, it produces tiny flashes of visible light. These flashes reveal where the particle traveled.

To locate the exact position of each flash, scientists divide the detector into millions of tiny pieces. Optical fibers collect the light from every section and send it to sensitive sensors that count individual photons.

This method works very well, but building these detectors is incredibly difficult.

For example, Japan's T2K neutrino experiment uses around 2 million tiny cubes connected by 60,000 optical fibers. Other experiments at CERN also rely on millions of thin fibers to achieve extremely high precision.

Although these detectors are highly accurate, they are expensive, difficult to manufacture, and challenging to expand.

A Completely New Idea

Instead of dividing a detector into millions of tiny parts, the Swiss research team asked a simple question:

What if one large block could do the entire job?

Their answer became PLATON.

Rather than tracking light from separate detector pieces, PLATON uses one solid block of scintillator and an advanced camera system that figures out exactly where each tiny flash of light originated.

This makes the detector much simpler while maintaining excellent accuracy.

Inspired by Light-Field Cameras

The key technology behind PLATON comes from light-field cameras, also called plenoptic cameras.

Unlike ordinary cameras that only record brightness and color, light-field cameras also measure the direction from which light arrives.

Because they know where light is coming from, these cameras can reconstruct objects in three dimensions.

To achieve this, they use thousands of microscopic lenses placed in front of the camera sensor.

Each tiny lens captures the same scene from a slightly different angle. A computer then combines all these views to build a detailed 3D image.

Scientists realized this technology could also reconstruct the paths of invisible particles inside a detector.

Detecting Even a Few Photons

Inside the scintillator, the light produced by particles is incredibly weak.

Sometimes only a handful of photons are created.

To detect these faint signals, PLATON uses an advanced imaging sensor called SwissSPAD2.

This sensor is so sensitive that it can detect single photons—the smallest possible units of light.

Even better, it only records photons during carefully selected time windows, reducing unwanted background signals and making genuine particle events easier to identify.

Successful Laboratory Tests

The researchers tested PLATON using extremely low light levels.

Some experiments produced several hundred photons, while others generated as few as five photons.

They also used radioactive strontium-90 to produce electrons and checked whether PLATON could correctly determine their positions inside a plastic scintillator block.

The detector successfully reconstructed the particle positions, and computer simulations closely matched the laboratory results.

This gave scientists confidence that the technology works exactly as expected.

The Next Generation Will Be Even Better

The current prototype is only the beginning.

Researchers are already developing a much more advanced version of PLATON.

The upgraded detector will record the exact arrival time of every individual photon, with timing accuracy better than one billionth of a second.

Instead of grouping photons into fixed time windows, every photon will receive its own timestamp.

This additional timing information will allow the detector to reconstruct particle tracks with even greater precision.

Scientists are also redesigning the camera optics to collect more light and expand the detector's field of view.

AI Helps Rebuild Invisible Particle Paths

One of the most exciting parts of PLATON is its use of artificial intelligence.

The research team developed a neural network based on the Transformer architecture, the same type of AI technology used in many modern large language models.

Instead of understanding words or sentences, this AI studies patterns in the detected photons.

It analyzes where each photon appeared and exactly when it arrived.

By finding hidden relationships among thousands of photon signals, the AI can reconstruct the original particle interaction in remarkable detail.

In simulations, the upgraded PLATON detector achieved better than 1 millimeter spatial resolution inside a detector measuring just 10 × 10 × 10 centimeters.

Scaling Up to Giant Detectors

Scientists also explored what would happen if PLATON were expanded to a detector measuring one cubic meter.

Even at this much larger size, computer simulations showed the detector could still achieve resolution of only a few millimeters.

That performance is similar to today's best plastic scintillator detectors—but without requiring millions of tiny detector pieces.

Researchers believe future improvements in optics and AI could eventually push even these giant detectors below 1 millimeter resolution.

More Than Just Particle Physics

PLATON's technology may have applications far beyond physics laboratories.

One of the most promising areas is Positron Emission Tomography (PET), a medical imaging technique widely used to detect cancer, study brain activity, and examine organs.

Since PET scanners also detect tiny flashes of light, PLATON's highly accurate 3D imaging technology could produce sharper images, improve diagnosis, and potentially reduce scanning times.

The research team has already filed three patents covering PET scanner designs and AI-based image reconstruction methods based on PLATON.

A Technology With a Bright Future

Particle physics has often produced inventions that later changed the world.

The World Wide Web was invented at CERN, and advances in particle accelerators led to proton therapy, a life-saving cancer treatment.

PLATON could become the next technology to make that journey.

By combining light-field imaging, ultra-sensitive photon detectors, and powerful AI, scientists have shown that it is possible to track invisible particles in 3D without building impossibly complex detectors.

If future experiments confirm its full potential, PLATON could transform the way scientists study neutrinos, search for dark matter, explore the universe's biggest mysteries, and even improve medical imaging for millions of patients worldwide.

Sometimes, the biggest scientific breakthroughs don't come from discovering something entirely new—they come from combining existing technologies in a brilliant new way. PLATON is a perfect example of that future taking shape.

Reference:

1. Till Dieminger, Saúl Alonso-Monsalve, Christoph Alt, Claudio Bruschini, Noemi Bührer, Edoardo Charbon, Kodai Kaneyasu, Tim Weber, Matthew Franks, Davide Sgalaberna. An ultrafast plenoptic-camera system for high-resolution 3D particle tracking in unsegmented scintillators. Nature Communications, 2026; 17 (1) DOI: 10.1038/s41467-026-70918-x