Cephalopod-inspired polymer composites with mechanically tunable infrared properties

Area of Science:

• Materials Science
• Biomimetics
• Soft Robotics

Background:

• Cephalopods possess dynamic, all-soft skin capable of rapid color changes for various functions.
• Mimicking these color-changing abilities in the infrared (IR) spectrum is crucial for advanced technologies like adaptive camouflage and flexible displays.
• Integrating tissue-like mechanics with rapid IR modulation in smart materials presents significant challenges.

Purpose of the Study:

• To develop an all-soft adaptive infrared composite inspired by cephalopod skin.
• To achieve dynamic control over IR appearance through mechanical deformation.
• To explore applications in emerging soft electronic technologies.

Main Methods:

• Created a biomimetic composite using liquid metal droplets (chromatophore analog) within an elastic elastomer (dermal layer analog).
• Utilized equiaxial stretching to induce transitions in liquid metal inclusions between droplet and platelet states.
• Investigated the resulting changes in IR reflectance and emissivity.

Main Results:

• Demonstrated a reversible change in the composite's IR appearance upon stretching.
• Observed transitions of liquid metal inclusions from corrugated droplets to smoother platelets.
• Successfully demonstrated strain-actuated flexible IR displays and pneumatically-driven soft devices with dynamic IR modulation.

Conclusions:

• The developed all-soft adaptive IR composite successfully mimics cephalopod skin's dynamic IR modulation capabilities.
• This material offers a promising platform for advanced soft electronics, including adaptive camouflage and flexible displays.
• The biomimetic approach provides a viable strategy for creating smart materials with tunable IR properties.