Multilaminate piezoelectric PVDF actuators to enhance performance of soft micro robots

TL;DR

This paper presents multilayer PVDF piezoelectric actuators with optimized design parameters, achieving high deflection, force, and frequency at low voltages, and demonstrates their application in robust soft microrobots.

Contribution

It introduces a novel multilayer PVDF actuator design with detailed characterization and modeling, enabling improved performance for soft microrobotic systems.

Findings

Achieved >3 mm free deflection and >20 mN force at >=500 Hz

Demonstrated low-voltage operation at 150 volts

Integrated actuators into a resilient microrobot for locomotion

Abstract

Multilayer piezoelectric polyvinylidene fluoride (PVDF) actuators are a promising approach to enhance performance of soft microrobotic systems. In this work, we develop and characterize multilayer PVDF actuators with parallel voltage distribution across each layer, bridging a unique design space between brittle high-force PZT stacks and compliant but lower-bandwidth soft polymer actuators. We show the effects of layer thickness and number of layers in actuator performance and their agreement with a first principles model. By varying these parameters, we demonstrate actuators capable of >3 mm of free deflection, >20 mN of blocked force, and >=500 Hz, while operating at voltages as low as 150 volts. To illustrate their potential for robotic integration, we integrate our actuators into a planar, translating microrobot that leverages resonance to achieve locomotion with robustness to large perturbations.