Session: SYMP 3-5: Actuator Systems

Paper Number: 141359

141359 - Dynamic Response of Zipping Gap Electrostatic Actuators 

In the evolving field of soft robotics, the advent of novel electrostatic (ES) actuators employing fluidic gaps has marked a significant advancement, offering attributes such as high power density, rapid response, and cost-effectiveness. These actuators utilize dielectric fluids alongside flexible, insulating polymer-based thin films, which are deformed via the application of high electric fields.

Such devices have been implemented in different embodiments that exploit various architectures, including HASEL (Hydraulically Amplified Self-healing Electrostatic Actuators), Electro Ribbon actuators, Electrostatic Bellow Muscles, and HAXEL (Hydraulically Amplified eXtensible Electrostatic actuators). All of these are leveraging the deformation of fluid polymeric films induced by Coulomb attraction forces applied on the surface of such polymeric layers.

This presentation focuses on ES actuators that employ a fluid gap and make use of polymeric thin film dielectrics combined with zipping kinematics. By adopting a zipping gap kinematics approach, these actuators introduce a smooth, progressive variation of their capacitance, enabling easy control through electrical input. Such actuators have demonstrated quite high dynamic capabilities in terms of high-frequency response.

In the first part of this study, we analyze the dynamic behavior of various liquid gap actuators that differ by the types of materials employed for the dielectric layers. Experiments are conducted using a dedicated setup to identify the dynamic response, and an electrical model is introduced that can explain the different responses of various material combinations.

It is shown that through careful selection of materials and optimization of geometric designs, it is possible to significantly improve the efficiency and responsiveness of ES actuators for their intended applications.

In a second part of this work, we addresses the technical challenges and potential solutions associated with the development and application of these types of actuators in the field of space technology. Experiments of zipping gap ES actuators operating in a vacuum environment are illustrated. Specifically, we developed a custom vacuum setup that includes the ES actuator in a vacuum apparatus equipped with a controlled loading system, sensing, and data acquisition unit that makes it possible to characterize the static and dynamic behavior of zipping gap electrostatic actuators.

The response of the actuator at variable frequencies is analyzed, demonstrating the proposed actuator design's capability to operate over a wide 0 to 100 Hz frequency range.

Future perspectives for the development of zipping gap ES actuators in space are also introduced discussing possible challenges in material developments, novel manufacturing/assembly procedures and scalability of the proposed ES technology. 

Presenting Author: Marco Fontana Scuola Superiore Sant'Anna

Presenting Author Biography: Marco Fontana received the Ph.D. degree in robotics from Scuola Superiore Sant’Anna, Pisa, Italy, in 2008.
He is currently an Associate Professor in Mechanical Engineering with Scuola Superiore Sant’ Anna. His main research interests include the development and optimization of innovative hardware solutions for advanced robots, mechatronic systems, and energy harvesters.

Authors:

Marco Fontana