Diamonds recovered from plastic contain roughly 3,000 atoms each and could be modified with other elements for future use in medical imaging.
Powerful lasers can turn plastic into tiny diamonds, but recovering the crystals means catching them as they shoot out at speeds comparable to a meteorite impact. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the University of Rostock have now collected those diamonds intact, showing that they survive the return from extreme pressure and temperature to ordinary conditions.
The recovered particles averaged three nanometers across, or three billionths of a meter, with roughly 3,000 carbon atoms in each diamond. The laser technique produces a combination of high purity, exceptionally small size, and closely matched particle sizes that conventional methods, including explosions, cannot achieve.
Diamonds form faster than expected
The work began with experiments designed to simulate conditions inside planets such as Neptune and Uranus, where temperatures reach several thousand degrees Celsius and pressures are millions of times higher than Earth’s atmospheric pressure. Firing high-power lasers at plastics created conditions in which carbon formed diamonds, although the researchers could initially detect the crystals only briefly while those extreme conditions lasted.
“We did expect nanodiamonds to form under these conditions. What surprised us, however, was how quickly it happened, which immediately sparked the idea of a potential technical application,” says Dominik Kraus, founding director of the new HEDI Institute of High Energy Density Physics at HZDR and a professor at the University of Rostock.
A soft landing for speeding diamonds
To recover particles for closer study, the team worked at the Extreme Light Infrastructure (ELI) south of Prague, a laser facility that combines very high pulse energies with a high repetition rate. At its L4n-P3 facility, a high-power laser fired three times per minute at a PET plastic film just 100 micrometers thick, about 0.004 inches. As the beam scanned across the film, each pulse generated a shock wave that compressed the plastic, formed nanodiamonds, and sent them toward a collection cylinder.
“When the compression wave reaches the end of the sample, it abruptly enters a vacuum, accelerating the nanodiamonds to speeds of more than ten kilometers per second – comparable to a meteorite impact. To prevent the diamonds from immediate destruction upon impact with the collection cylinder, we need to use a very soft collection medium,” Kraus says.
To cushion particles arriving at more than 22,000 miles per hour, the team chose a water-soluble ionic gel that could function in a vacuum. The diamonds could then be extracted from the gel and purified for examination.
Even with approximately ten trillion diamonds produced per laser shot, the team needed around 100 shots to collect a few hundred micrograms of material. That was enough to identify and characterize the particles using the ELMI-MV electron microscope at the University of Rostock’s Department Life, Light, & Matter.
“After extracting the nanodiamonds from the catcher material and purifying them, we were able to see them for the first time directly using the ELMI-MV. That was a special moment we had been working towards for years. With this instrument, we can even resolve individual atoms,” says Ben Heuser of HZDR, the study’s primary author, who conducted the experiments as part of his doctoral thesis at the University of Rostock.
Smaller diamonds could speed chemical reactions
Hard, stable, and resistant to heat, nanodiamonds are already used in grinding and polishing agents. Producing smaller, cleaner particles with more consistent sizes could expand their applications in medicine, new materials, and energy technology. Potential uses include highly sensitive quantum sensors, which exploit quantum effects to make measurements, and medical contrast agents that make features inside the body easier to see in scans.
Smaller diamonds also provide more combined surface area for a given amount of material, offering more space for chemical reactions. That could improve their efficiency as catalysts, which accelerate reactions, in processes such as splitting CO₂ with sunlight. Starting with plastic also makes it easier to incorporate atoms of other elements into the diamonds, a process called doping. These additions could tailor the particles for particular tasks, including improving contrast agents for medical MRI examinations.
More laser pulses, more diamonds
Fusion research is driving the development of more energy-efficient lasers capable of delivering powerful pulses more frequently. Applying those advances to nanodiamond production could increase output by allowing more shots in less time, potentially making the process scalable and supporting cleaner, more sustainable manufacturing. Through further experiments in their laboratories at the University of Rostock and at large-scale research facilities, the researchers aim to bring production into the milligram range, a quantity comparable to conventional production processes.
The team also wants to use laser compression to make BC8, a form of carbon that has so far only been predicted theoretically. It is expected to be denser than diamond, similarly hard, and less brittle. The conditions needed to form it do not occur naturally on Earth, so the researchers hope to create it directly from plastic by applying still higher pressures with powerful lasers in an initial experiment planned for November.
Reference: “Recovery of ultrasmall nanodiamonds from plastics shock-compressed to pressures around 100 GPa” by B. Heuser, P. Böhringer, K. Oldenburg, F.P. Condamine, G. Fauvel, M.-L. Herbert, J. Kuhkle, T. Laštovička, P. Luckmann, J. Lütgert, P.T. May, D. Ranjan, S. Schumacher, R.L. Singh, M. Stevenson, S. Weber and D. Kraus, 25 August 2026, Diamond and Related Materials.
DOI: 10.1016/j.diamond.2026.114091
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