Semiordered Hierarchical Metallic Network for Fast and Large Charge-Induced Strain

Area of Science:

• Materials Science
• Nanotechnology
• Robotics

Background:

• Polymer actuators have low operating voltage but limited performance.
• Piezoceramics offer high performance but require high voltage.
• Metallic actuators present a potential alternative bridging this gap.

Purpose of the Study:

• To develop a nanoporous metallic actuator with enhanced strain amplitude and accelerated switching.
• To investigate the structure-property relationships of the metallic actuator for artificial muscle applications.

Main Methods:

• Fabrication of a 3D macroscopic metallic actuator with a semiordered and hierarchical nanoporous structure.
• Characterization of the nanoarchitecture, including μm-sized tubes and nm-sized ligaments.
• Evaluation of actuation performance, including strain amplitude, strain rate, and cyclic stability.

Main Results:

• Achieved a record reversible strain amplitude of 1.59% with a strain rate of 8.83 × 10^-6 s^-1.
• The unique nanoarchitecture facilitates fast ion transport and high charge storage.
• A self-grown hydroxide layer enhances supercapacitance and structural stability.

Conclusions:

• The developed nanoporous metallic actuator demonstrates superior performance for artificial muscle applications.
• The hierarchical nanoarchitecture and self-grown hydroxide layer contribute to enhanced strain, speed, and durability.
• This technology offers a promising low-voltage, high-performance alternative to existing actuator technologies.