How Does the Inner Geometry of Soft Actuators Modulate the Dynamic and Hysteretic Response?

TL;DR

This study explores how the internal geometry of soft pneu-nets influences their dynamic response and hysteresis, demonstrating that strategic design modifications can significantly improve performance and control in soft robotics.

Contribution

It introduces a method to optimize soft actuator geometry to enhance dynamic response and reduce hysteresis, validated through FEM simulations and experimental testing.

Findings

Design with minimum air chamber width improves hysteresis by 21.5%.

Dynamic response increases by 60% to 112% across various frequencies.

Achieves 95% accuracy in predicting bending angles up to 500% strain.

Abstract

This paper investigates the influence of the internal geometrical structure of soft pneu-nets on the dynamic response and hysteresis of the actuators. The research findings indicate that by strategically manipulating the stress distribution within soft robots, it is possible to enhance the dynamic response while reducing hysteresis. The study utilizes the Finite Element Method (FEM) and includes experimental validation through markerless motion tracking of the soft robot. In particular, the study examines actuator bending angles up to 500% strain while achieving 95% accuracy in predicting the bending angle. The results demonstrate that the particular design with the minimum air chamber width in the center significantly improves both high- and low-frequency hysteresis behavior by 21.5% while also enhancing dynamic response by 60% to 112% across various frequencies and peak-to-peak pressures. Consequently, the paper evaluates the effectiveness of "mechanically programming" stress distribution and distributed energy storage within soft robots to maximize their dynamic performance, offering direct benefits for control.