A Soft Actuator with Simultaneous Ultra-High Actuation Strain and Power Density Under Human-Safe Stimuli

Area of Science:

• Materials Science
• Robotics
• Polymer Chemistry

Background:

• Soft actuators are crucial for diverse applications like wearable devices and biomedical systems.
• Existing soft actuators fail to meet the combined requirements of high actuation strain and power density under mild stimuli.

Purpose of the Study:

• To design and develop a novel soft actuator system that simultaneously delivers high actuation strain and power density.
• To address the limitations of current soft actuators in responding to human-safe stimuli.

Main Methods:

• Macromolecular engineering of lightly crosslinked gels to create a thickness-direction orientation gradient in liquid crystalline elastomer (LCE) films.
• Utilizing ultrahigh stretch ratios (up to 2000%) and controlled entropic recovery to establish molecular orientation.
• Developing fully crosslinked monodomain LCE soft actuators responsive to body-temperature stimulation.

Main Results:

• Achieved a high actuation strain of 88% and a power density of 1960 W kg^-1.
• Demonstrated performance exceeding existing soft actuators sensitive to mild stimuli.
• Successfully integrated the LCE actuator in device-level demonstrations, including a rotary soft robot and an intelligent safety switch.

Conclusions:

• The novel body-temperature-responsive LCE soft actuator overcomes previous limitations, offering unprecedented performance.
• The developed actuator technology holds significant potential for real-world integration in advanced soft robotic systems.
• This breakthrough paves the way for next-generation soft robotics with enhanced capabilities.