ITMO researchers used their new laser painting method to make a miniature version of Vincent van Gogh’s painting “The Starry Night.” [Image: Yaroslava Andreeva]
The coherent, precisely directed light emitted by lasers has become indispensable to fields like medicine, science and telecommunications. Lesser known, perhaps, is the technology’s substantial impact in the art world. Lasers can cut intricate patterns in materials like paper, wood or metal and restore old artwork through ablation and cleaning techniques.
Now, a team of Russian researchers has developed a laser paintbrush for artists and designers that creates, erases and changes the colors of strokes on a titanium canvas (Optica, doi: 10.1364/OPTICA.420074). The tool doesn’t require any external colorants and creates pieces that are extremely resistant to harsh environments and chemicals.
A color palette
Yaroslava Andreeva and her colleagues had previously created a laser-based device that used oxidation to generate a complete color palette on stainless steel. Essentially, an oxide layer of a certain thickness and chemical composition is formed on top of the metal surface. Interference occurs between the light reflected from the top and bottom surfaces of the oxide film, which allows only certain wavelengths of light to be observed.
Once they discovered the right parameters needed for each color, the researchers wanted to take the project a step further by inventing a new tool to make art.
“We were impressed by how a real artist works with paints, brushes and other materials. Usually an artist has the opportunity to use different colors from a palette, mix colors, and sometimes the erasing of some fragments is needed,” said Andreeva, an engineer at ITMO University in Russia. “So our work started from the development of these three main artistic operations.”
Creating, erasing, rewriting
The team built a makeshift printer that takes an image as input and, after running it through a computer algorithm, could produce a laser-made titanium artwork of the same image. It consists of a nanosecond ytterbium fiber laser system equipped with a two-axis galvanometric scanner that could move the beam line-by-line within a 110×110 mm area.
To create strokes, the laser paintbrush heats up the titanium surface to the point where it evaporates, and when the metal cools, a thin oxide layer forms. It could access 25 to 30 different colors, with thicker films appearing blue and thinner films appearing red or orange.
Andreeva and her colleagues noticed that a second laser pass with increased scanning speed led to the reduction of color brightness. After tweaking the intensity and scanning speed a bit further, they hit upon a combination that led to the complete disappearance of visible color on the surface. Similarly, retreatment of the same area with multiple passes allowed for the changing of colors.
Developing a handheld tool
To demonstrate their laser paintbrush, the researchers created miniature renditions of famous masterpieces such as Vincent van Gogh’s “The Starry Night,” which took a mere three minutes to produce. Next, the researchers hope to fabricate a handheld tool for artists and designers to use much like a pen or a real paintbrush.