Innovation That Matters

| Photo source Fujii Minoru

Nature-inspired inks for painting planes and more

Sustainability

The nanomaterial-based ink delivers permanent colours at a fraction of the weight of conventional paint

Spotted: In traditional materials science, colour comes from molecules absorbing specific colours from white light. Over time, the molecules degrade and the colour fades. However, colour in some natural materials, such as butterfly wings or bird feathers, occurs when light is reflected from nanostructures that let through only light of certain wavelengths while cancelling others out. This type of colour does not degrade over time, which is why feathers don’t dull as a bird ages.

Natural colours rely on the precise three-dimensional arrangement of nanostructures, which is impractical for industrial applications, such as printing onto and coating surfaces. Now, however, researchers Professor Fujii Minoru and Associate Professor Sugimoto Hiroshi, at Kobe University, have developed a colloidal suspension of spherical and crystalline silicon nanoparticles, which can be used to create long-lasting ink colours.

Hiroshi told Springwise how this is achieved, explaining that: “The single silicon nanoparticles exhibit bright scattering colours by ‘Mie resonance,’ which allows us to develop ‘structural colour inks.’” The ink containing the sparsely distributed silicon nanoparticles has a thickness of only 100-200 nanometres and weighs less than half a gramme per square metre. This makes it one of the lightest colour coats in the world.

Hiroshi suggested that applications for the inks could include use in anti-counterfeiting, semi-permanent colouring that does not fade, and cosmetic applications. “We are planning to scale this up for commercial mass production. In this way, we continue to conduct research, including industry–academia collaborations, not only for generating academic results but also for realising practical applications.”

Pigments and paints are getting something of a makeover lately, with innovations from eco-paints made using graphene to energy-saving paints inspired by butterflies featured in the Springwise library.

Written By: Lisa Magloff

Email: sugimoto@eedept.kobe-u.ac.jp

Website: kobe-u.ac.jp

Contact: kobe-u.ac.jp/contact

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