Lifetime of HASEL Actuators
Updated: Jan 31, 2022
HASEL actuator lifetime is a common discussion point when reviewing specifications. This critical metric can mean a lot of things depending on the application, but one useful way to measure lifetime is in cycles to failure, which is appropriate for numerous applications where actuators undergo cyclic operation.
There is no single number for the lifetime of a HASEL actuator as it depends on many factors, such as:
Operating conditions (driving voltage, frequency, etc.)
Additionally, actuator failure generally occurs due to dielectric breakdown in the insulating materials. These dielectric breakdown processes are inherently statistical in nature, leading to a distribution of lifetime values, often following a Weibull distribution.
A key advantage of HASEL actuators is their ability to use materials that are inexpensive yet have excellent dielectric properties, such as thin polymer films widely used in the high-performance capacitor industry. These materials give Artimus electric linear actuators the potential to achieve very high cycle lifetimes. Current HASEL actuators have average lifetimes that range anywhere from tens of thousands of cycles to millions of cycles, depending on their design and the demands of the particular application.
Artimus Robotics recently completed a Phase I SBIR award from the National Science Foundation (NSF) that focused on characterizing failure modes in HASEL actuators and improving their lifetime. The lifetime was doubled throughout the course of the grant (Figure 1). Additional geometry and material optimization - and efforts to suppress common failure modes of linear electric actuators - led to proof of concept actuators with up to 20x higher lifetime (Figure 1). HASEL technology is continuously improving, and through strategic partnerships, we are working to further improve actuator lifetime for the demands of industrial and consumer applications.
There are a few strategies for customers looking to maximize the lifetime of their HASEL actuators:
Reduce the actuation voltage: reducing the actuation voltage will decrease the force output of actuators, but it will also increase their lifetime. Decreasing the actuation voltage from 8kV to 6kV can lead to a 10x increase in actuator lifetime for our C-5015 series actuators.
Avoid rapid changes to applied voltage: Actuation signals such as step functions create a larger electrical stress in the actuators and can lead to reduced lifetime. Using signals with a lower slew rate will generally increase the lifetime and reliability of actuators.
Ensure the electric linear actuator is properly sized for the application: Artimus Robotics specializes in optimizing actuators for specific applications. Contact Us to review the specifications with the engineers at Artimus Robotics.
The Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) programs are highly competitive programs that encourage domestic small businesses to engage in Federal Research/Research and Development (R/R&D) with the potential for commercialization. Through a competitive awards-based program, SBIR and STTR enable small businesses to explore their technological potential and provide the incentive to profit from its commercialization. By including qualified small businesses in the nation's R&D arena, high-tech innovation is stimulated, and the United States gains entrepreneurial spirit as it meets its specific research and development needs.
About Artimus Robotics
Artimus Robotics designs and manufactures soft electric actuators. The technology was inspired by nature (muscles) and spun out of the University of Colorado. HASEL (Hydraulically Amplified Self-healing ELectrostatic) actuator technology operates when electrostatic forces are applied to a flexible polymer pouch and dielectric liquid to drive shape change in a soft structure. These principles can be applied to achieve a contracting motion, expanding motion, or other complex deformations. For more information, please visit Artimus Robotics or contact firstname.lastname@example.org.