Researchers at ITMO University in St. Petersburg, Russia are blurring the lines between science and art by using a laser to create artistic ‘masterpieces’ in a way that mirrors classical painting and associated brush strokes. The new technique yields paint-like strokes of colour on metal that can be changed, erased and even ‘re-written.’
“We developed a way to use a laser to create localized colours on a metallic canvas using a technique that heats the metal to the point where it evaporates,” said research team leader Vadim Veiko. “With this approach, an artist can create miniature art that conveys complex meaning – not only through shape and colour, but also through various laser-induced microstructures on the surface.” In Optica, The Optical Society’s (OSA’s) journal for high-impact research, Veiko and his colleagues showed that their new laser tools can be used to create unique colourful paintings. Research team member Yaroslava Andreev added: “We hope that laser painting will attract the attention of modern artists and lead to the creation of a completely new type of art. The approach can also be used for modern design and to create colour markings on various products.”
Painting with laser light
The new study builds on previous work in which the researchers investigated how to use lasers to create colour on titanium and stainless steel. “We wanted to do more than offer a wide palette of stable colours,” said Galina Odintsova, a member of the research team. “So we worked to create a convenient tool for applying them more like an artist’s brush.” For the new technique, the researchers heated the metal to a point where it started to evaporate – much higher than the melting temperatures used in previous approaches. When the metal cooled, an extremely thin film of metal oxide formed. Light reflected from the metallic surface and the top of the oxide film interferes in a way that produces different colours, depending on the thickness of the film. “Increasing the laser heating range enough to create the evaporation process makes our colour strokes reversible, rewritable, erasable and much more efficient,” Odintsova pointed out. “Plus, our marking speed is more than 10 times faster than reported before.”
The researchers used a nanosecond ytterbium fibre system equipped with a galvanometric scanner to create strokes that combine surface relief with optical effects, creating nine basic colours. (Ytterbium is a soft, malleable and ductile rare-earth element with a bright silvery lustre when pure. It oxidizes slowly in air.). A second pass of the laser at a faster scan rate can erase or change the colour of a specific area. Researchers demonstrated that the surface colour of erased areas was indistinguishable from a non-treated surface – and that colours could be erased and rewritten several times without affecting the final colour. The new laser paintbrush made the 3” x 2” version of Starry Night (above) in just four minutes! They also created original artwork to demonstrate colour mixtures and erasing capabilities.
Researchers further explained that pictures created using this new approach were extremely resistant to harsh environments and chemicals, and don’t require any type of special storage. Their ultimate goal was to incorporate the new laser-painting capabilities into a handheld tool that could be used much like a pen or paintbrush to create colourful images on metals or metallic foils. This approach can also be used to add nanostructured and hybrid materials or periodic surface gratings.