Low-Voltage-Driven Liquid Metal Microdroplet/Poly(vinyl Chloride) Gel Actuator for Smart Haptic Interaction...

Area of Science:

• Materials Science
• Robotics
• Biomedical Engineering

Background:

• Dielectric elastomer actuators (DEAs) offer low noise and large deformations for haptic interfaces.
• High driving voltages and in-plane actuation limit practical applications of DEAs.
• The dielectric constant-Young's modulus trade-off is a key challenge in DEA development.

Purpose of the Study:

• To overcome the dielectric constant-Young's modulus trade-off in DEAs.
• To enable large actuation strains at lower electric fields.
• To develop a low-voltage-driven haptic device with out-of-plane actuation.

Main Methods:

• Incorporation of modulus-near-zero liquid metal (LM) microdroplets into poly(vinyl chloride) gel (PVCG).
• Utilizing microscopic creep deformation and mesh-like electrodes to convert in-plane to out-of-plane actuation.
• Fabrication of a compact haptic device prototype using the modified PVCG actuators.

Main Results:

• Achieved large actuation strains under relatively low electric fields by overcoming the trade-off.
• Demonstrated a 1.6-time improvement in electromechanical coupling sensitivity and 1.8-time enhancement in out-of-plane displacement.
• The haptic device prototype exhibited 20% out-of-plane actuation strain and 1.5 kPa output stress at 3.75 V μm^-1.

Conclusions:

• The LM-modified PVCG actuator effectively overcomes key limitations of traditional DEAs.
• The developed haptic device shows significant potential for virtual reality, augmented reality, and assistive navigation.
• This work highlights a promising approach for low-voltage, high-performance haptic interface development.