Bio-inspired micro-architected mechanochromic materials with radiative signature modulation

Area of Science:

• Materials Science
• Metamaterials
• Nanotechnology

Background:

• Nature-inspired structural coloration faces challenges like the barreling effect in mechanical metamaterials.
• Existing methods for tunable reflectivity are often limited by material properties and fabrication complexities.

Purpose of the Study:

• To create a novel class of bio-inspired mechanochromic materials with tunable reflectivity across the electromagnetic spectrum.
• To overcome the barreling effect in mechanical metamaterials for uniform strain deformation.

Main Methods:

• Developed a mechanical metamaterial substrate optimized via genetic algorithm and modeled using Timoshenko beam theory.
• Fabricated a system with dielectric nanopillars on a micro-architected substrate using Multiphoton Lithography (MPL).
• Engineered nanopillars with a high-refractive-index coating to achieve complete optical band gaps.

Main Results:

• Demonstrated reversible elastic deformation to dynamically adjust lattice constants and shift reflected wavelengths.
• Successfully tailored structures for visible, mid-wave infrared (MWIR), and long-wave infrared (LWIR) spectral regions.
• Validated the scalability and robustness of the proposed mechanochromic material system.

Conclusions:

• The developed framework enables scalable, reversible mechanochromic materials inspired by nature.
• This technology holds significant potential for adaptive camouflage, radiative thermal management, and wearable electronics.
• The methodology provides a foundation for future advancements in tunable optical materials.