# Bioinspired maskless structural colour patterning via tunable nanoparticle segregation

## TL;DR

Scientists created a new method to make colorful patterns using nanoparticles inspired by bird feathers, which could lead to sustainable and multifunctional materials.

## Contribution

A one-step, mask-free method for structural color patterning using nanoparticle segregation inspired by bird feather melanosome self-assembly.

## Key findings

- Nanoparticle segregation during photocuring forms disordered layers that produce structural color.
- Grayscale printing controls segregation thickness for high-resolution color patterns and infrared camouflage.
- The method is scalable and suitable for visual display and information encryption.

## Abstract

Structural colouration arises from the interaction of light with nanoscale structures and offers sustainable alternatives to pigment-based colours. However, current structural colour patterning methods rely on multi-step lithographic processes or multiple ink formulations, limiting scalability and spatial resolution. Inspired by melanosome self-assembly in bird feathers, we develop a one-step, mask-free strategy to generate high-resolution structural colour patterns via tunable nanoparticle segregation. During photocuring, silica nanoparticles dispersed in acrylic resin migrate toward oxygen-permeable substrates, forming a nanoparticle-enriched disordered layer. Such segregation is driven by interfacial oxygen inhibition and kinetically governed by the photocuring rate. Using grayscale digital light processing printing, we programmably control the local segregation thickness to create high-resolution structural colour patterns for visual display and information encryption. The segregation structure also affects mid-infrared reflectivity, allowing for infrared camouflage. This scalable approach establishes a mechanistically guided route to multifunctional photonic materials.

Structural colour offers an alternative to pigment-based colouration, but patterning often requires multiple steps. Here, the authors report a one-step, mask-free strategy for the formation of structural colour patterns based on manipulation of a nanoparticle enriched disordered layer.