UV and IR dual light triggered cellulose-based invisible actuators with high sensitivity

Area of Science:

• Materials Science
• Nanotechnology
• Robotics

Background:

• Actuators are crucial for bionic devices and soft robots.
• Invisible actuators offer unique applications, including covert operations.

Purpose of the Study:

• To develop transparent, UV-absorbing cellulose-based films.
• To fabricate a novel transparent actuator sensitive to UV and IR light.

Main Methods:

• Dissolving cellulose using N-methylmorpholine-N-oxide (NMMO).
• Incorporating ZnO nanoparticles for UV absorption.
• Growing a hydrophobic polytetrafluoroethylene (PTFE) film on a regenerated cellulose (RC)-ZnO composite film.

Main Results:

• The actuator exhibits sensitive responses to both UV and IR light due to ZnO nanoparticles.
• Asymmetric assembly leveraging differential water adsorption leads to high sensitivity.
• Achieved a force density of 60.5, maximum bending curvature of 3.0 cm⁻¹, and response time under 8 seconds.
• Demonstrated applications in bionic bugs, smart doors, and excavator arms.

Conclusions:

• The developed transparent actuator shows excellent performance and sensitivity to UV and IR light.
• The material is suitable for advanced applications in soft robotics and bionic systems.
• ZnO nanoparticles and PTFE/RC composite structure are key to the actuator's functionality.