Ultralow Voltage High-Performance Nanocellulose-Based Electro-Ionic Actuators for Soft Robots

Area of Science:

• Materials Science
• Robotics
• Nanotechnology

Background:

• Development of high-performance, eco-friendly soft actuators is crucial for advanced bioinspired soft robots.
• Existing actuators often face limitations in displacement, response time, or operational lifespan.

Purpose of the Study:

• To create a novel electro-ionic soft actuator with enhanced performance characteristics.
• To explore its potential applications in bioinspired robotics and biomedical devices.

Main Methods:

• Fabrication of an electro-ionic soft actuator using carboxylated cellulose nanocrystals (CCNC), carboxylated cellulose nanofibers (CCNF), graphene nanoplatelets (GN), and ionic liquid (IL).
• Characterization of actuation performance, including displacement, response time, frequency band, and long-term stability.
• Demonstration of bioinspired applications such as micro-grippers, stents, and robotic wings.

Main Results:

• Achieved large displacements (1.6–12.3 mm) at ultralow voltages (0.25–1.5 V).
• Demonstrated stable operation across a wide frequency band (0.1–10 Hz) with 99.3% stability over 240 cycles.
• Exhibited a fast response time (0.39 s delay) and exceptional long-term lifespan (2% decrease over 2 years).

Conclusions:

• The CCNC/CCNF-IL-GN actuator offers superior ionic conductivity, charge storage, and network stability, leading to enhanced performance.
• Successfully demonstrated bioinspired applications, highlighting the actuator's versatility.
• Presents a significant advancement for eco-friendly soft actuators, soft robots, and biomedical microdevices operating in low-voltage environments.