Design of a High-Speed Prosthetic Finger Driven by Peano-HASEL Actuators

Area of Science:

• Biomedical Engineering
• Robotics
• Materials Science

Background:

• Current prosthetic limbs predominantly use DC motors, limiting design and functionality.
• Soft actuators present an alternative for creating more biomimetic and capable prosthetic devices.

Purpose of the Study:

• Evaluate the performance of a hydraulically amplified self-healing electrostatic (HASEL) soft actuator for prosthetic hand applications.
• Compare the Peano-HASEL actuator to DC motors in driving a prosthetic finger.
• Investigate methods to improve the force output of HASEL actuators for prosthetic use.

Main Methods:

• Developed and validated a kinematic model for a prosthetic finger.
• Customized a prosthetic finger to match Peano-HASEL actuator characteristics.
• Utilized an analytical model to redesign the Peano-HASEL for increased fingertip force.

Main Results:

• The Peano-HASEL driven finger demonstrated 10.6x greater speed, 11.1x higher bandwidth, and 8.7x lower energy consumption for grasping compared to a weight-matched DC motor.
• Achieved 91% of the original finger's range of motion.
• The DC motor produced 10x greater fingertip force at a relevant grip position.

Conclusions:

• Peano-HASEL soft actuators offer significant advantages in speed, bandwidth, and energy efficiency for prosthetic hands over DC motors.
• While current force output is lower than DC motors, methods to increase it are presented.
• HASEL actuators provide a novel form-factor and performance profile, opening new avenues for upper-limb prosthetic design.