Researchers to develop printable, non-iridescent and lightweight ink

A coalition between Kobe University and the venture capital firm ANRI aims to commercialize a completely new way of creating colors. With their lightweight, unfading and environmentally friendly way of producing color, they want to first enter the security ink and cosmetics markets before moving on to paints for cars, airplanes and other mobility applications.

We color our world, and ourselves, to display information, to protect the underlying surface, to uniquely identify an object, and for many more reasons. But there are many problems, too. For one, conventional colors degrade over time, making frequent reapplication necessary.

Also, some of the pigments themselves and their solvents, as well as the energy necessary to dry away the solvent, have a range of environmental or health impacts. And many colors are not very opaque in their intended setting, so they need foundations or must be applied thickly, adding weight and further increasing the environmental impact.

The Kobe University material engineer Sugimoto Hiroshi has developed a completely new way of producing colors. "Using tiny silicon spheres of very consistent size, light can be scattered around these spheres so that only one color is reflected," he says.

He demonstrated that just a single layer applied to a glass surface produces bright and brilliant colors. And since they are not produced by light absorption, as in conventional pigments, but by scattering around a nanometer-sized, spherical silicon crystal, the colors also should neither fade nor depend on the viewing angle. Sugimoto says, "Then, we realized that this material lets us coat 3D objects in non-iridescent colors."

Teaming up with Kameda Takahiro from the venture capital firm ANRI, which is specialized in developing deep tech startups, Sugimoto went on to identify the needs of different paint-related markets and how his development could help them solve problems facing companies in these markets.

In a first step, they will aim to produce high value-added products that can only be created with this technology, such as security inks and raw materials for cosmetics.

"With our nanospheres we can theoretically achieve printing resolutions of up to 50,000 dpi (your office printer has a resolution of 300 dpi) which is well beyond the 10,000 dpi required for the most advanced security inks," explains Sugimoto.

"For the cosmetics industry, they are the only raw product that can combine the functions of pigments and concealers in foundations and sunscreens. Also, silicon being the second most abundant element in the Earth's crust, humans are taking it in daily without any health effects."

A first plant for this purpose is planned to be constructed and start production in 2027.

After having established production technologies and sales networks, they want to expand to the mobility industry with a second plant planned for 2029.

Sugimoto says, "Between a quarter and a third of the greenhouse gas emissions during the production of a car stem from the coloring process, because it takes so much energy to dry the thick layers of paint. Likewise, for airplane manufacturers, the thick layer of paint adds several hundreds of kilograms to the plane's weight, which increases its fuel consumption.

"In both cases, due to their opacity, our nanospheres would require a much thinner layer and so we can significantly reduce costs and environmental impact."

There is one more advantage to the nanospheres being made of silicon.

"In addition to its low environmental impact, silicon is a fundamental material for the semiconductor industry, and therefore has a high affinity with industrial technology in addition to there already being abundant physical and chemical knowledge," says Sugimoto. And if the material can be sourced from waste products of the semiconductor industry, it will further benefit the environment over the whole value chain.

They aim for an initial public offering until 2033, by which time they hope to achieve market shares of up to 20% in some of their markets.

More information:
"Structural color ink: Printable, non-iridescent and lightweight"

Provided by Kobe University