Seeing the unseen: Trinity team builds game-changing particle impact machine

Posted on: 24 July 2025

The Laser Ablation Particle Acceleration and Observation (LAPAO) machine, built by Trinity’s Science & Technology in Advanced Manufacturing (STAM) research group, uses a laser to fire particles of 10–60 microns in size at speeds of up to 1 km per second, which is about three times faster than a bullet. 

A special camera, taking a billion pictures per second, then captures how these particles behave when they hit a surface: do they stick, bounce, or break? 

Answers to that core question are important because they will help engineers understand how to make better materials and coatings — the kind used in things like aircraft parts, medical implants, or even protective layers for machinery. The process they’re improving is called “Cold Spray”, which is a way of “printing” or repairing metal parts without needing to melt them.     

Until now, they could only guess at this based on computer models. With this machine, they can finally see what’s really happening — and that’s a game-changer for how they design and manufacture advanced materials. 

Leo Devlin, PhD Candidate in Trinity’s School of Engineering, and a key member of the STAM team, said: “Thanks to our machine we can now obtain material parameters for micro-particles undergoing ultra-high strain rate plastic deformation, which is something that modellers have been attempting to predict for a very long time. Due to software limitations, however, they have not been able to predict particle behaviour with a high enough degree of accuracy.”

“With this machine we can visualise real material interactions for a wide range of particle and substrate materials in minutes, which will aid us in understanding and optimising the cold spray process for specific materials. To date the machine has been used to find the critical velocity for a range of materials such as aluminium, Ti64 and high entropy alloy, which are used in the electrical and automotive industries as coatings which can lead to lightweight parts with more desirable material properties such as high wear and corrosion resistance.”

Over the past few years, cold spray technology has evolved into advanced variants such as laser-assisted and electromagnetism-assisted cold spray, to improve the microstructure and performance of deposited materials.

Cold spray tech enables the formation of coatings, typically metallic, over a substrate material. The technique is highly useful as it does not require engineers to reach the melting temperature of materials to combine the coatings and substrates. Plastic deformation is key in this process; each tiny particle deforms on impact and triggers a complex bonding process that results in substrate adhesion and in particle-particle adhesion after a first deposition layer is formed.

“Today, beyond its traditional use in the aerospace industry, cold spray is also being applied in the nuclear, automotive, and broader manufacturing sectors, added Prof. Shuo Yin, from the STAM team in Trinity.

“In addition, this new machine can also be used to simulate other high-velocity microscale impact events, such as debris impacts on satellites in space, which is a growing problem with ever-increasing junk material orbiting the planet along with very important – and expensive – equipment.”

“That’s one of the most exciting elements of this news – the machine’s abilities will help researchers with a wide variety of interests learn more about particle behaviours relevant to their nice area of focus. As such the application and impact potential is huge.”

Prof. Rocco Lupoi, from the STAM team in Trinity, said: “Any particle impact can now be studied using any real shape, and we are already using this technology in an EU-funded project called MadeCold, which is developing a new type of cold spray based upon electrostatic acceleration of single particles. LAPAO is now providing clear indications about the precise velocity needed for bonding and giving us key information about the relationship between particle material and morphology.”

For more information about MadeCold, see: https://www.madecold.eu/.

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