Pixelating Responsive Structural Color via a Bioinspired Morphable Concavity Array (MoCA) Composed of 2D Photonic...

Area of Science:

• Materials Science
• Optics
• Soft Robotics

Background:

• Stimuli-responsive structural coloration enables color change in soft materials due to environmental factors like heat and solvents.
• These color-changing systems are vital for smart soft devices, including camouflage for soft robots and chromatic sensors for wearables.
• A key challenge is achieving individually programmable, stimuli-responsive color pixels for dynamic displays.

Purpose of the Study:

• To design a morphable concavity array for pixelating structural color in 2D photonic crystal elastomers.
• To achieve individually and independently addressable stimuli-responsive color pixels.
• To demonstrate dynamic display capabilities for applications like anti-counterfeiting and encryption.

Main Methods:

• A morphable concavity array was designed, inspired by butterfly wing structures.
• The concavity surface transitions between concave and flat states in response to solvent and temperature changes, causing angle-dependent color shifts.
• Multichannel microfluidics were employed to control the color switching of individual concavities.

Main Results:

• The developed system successfully pixelates structural color, enabling independent control of each pixel's response to stimuli.
• Dynamic displays were demonstrated by forming reversible letters and patterns.
• The strategy of pixelating optical properties via localized surface topography alteration was validated.

Conclusions:

• The novel morphable concavity array addresses the challenge of individually addressable stimuli-responsive color pixels.
• This approach offers potential for advanced applications in dynamic displays, anti-counterfeiting, encryption, and biomimetic optical devices.
• The strategy can inspire the design of new transformable optical devices for robotics and other fields.