Smart Bioinspired Actuators: Crawling, Linear, and Bending Motions through a Multilayer Design

Area of Science:

• Materials Science
• Robotics
• Polymer Science

Background:

• Ionic electroactive polymer (IEAP) actuators are key for wearable tech due to their energy conversion capabilities.
• Current trilayer designs limit actuators to bending, hindering complex motions and low-voltage applications.
• Nonlinear responses in IEAPs restrict their full potential in next-generation devices.

Purpose of the Study:

• To introduce a novel multilayer IEAP actuator design for complex, biomimetic deformations.
• To overcome limitations of traditional trilayer designs for enhanced actuator functionality.
• To achieve high-performance linear motion in soft actuators at low driving voltages.

Main Methods:

• Fabrication of a multilayer soft actuator with a hierarchically ordered porous stretchable interlayer.
• Electromechanical characterization under low-voltage (3 V) ambient conditions.
• Performance testing including actuation strain, switching speed, cycle stability, and blocking force.

Main Results:

• Achieved 6.5% linear actuation strain with rapid 0.8 s switching speed.
• Demonstrated stable performance over 5000 cycles in air.
• Produced 4.2 mN linear blocking force at ±3 V, enabling low-voltage linear motion.
• Successfully demonstrated a walkable spider robot powered by the actuators.

Conclusions:

• The new multilayer design enables complex deformations, mimicking biological systems.
• The actuators exhibit excellent electromechanical properties and fast charging kinetics.
• This technology provides a platform for advanced soft robotics, wearable exosuits, and biomimetic devices powered by portable batteries.