HASEL actuators offer very unique motion compared to traditional actuators. Similarly unique is the linear actuator power supply. HASEL actuators are powered by high voltage Direct Current or DC. While the use of high voltage often leads one to think about large transformers and high power consumption, this is not the case with HASEL actuators. In fact, HASEL actuators operate with very low current and thus have extremely low electrical power consumption.
As is the case with many motion technologies, the electrical power consumption of HASEL actuators is dependent on the application and operating conditions. The key factors that dictate the amount of power consumed by the actuators are:
The driving voltage which corresponds to the mechanical force
The operating frequency or turn-on speed
The number/size of actuators dictates the mechanical performance.
Importantly, HASEL actuators are capacitive devices so their primary power consumption occurs only during the charging (or turn on) portion of an actuation cycle. When actuation is desired and a voltage is applied across the electrodes, the actuator draws current until it is fully charged and thus fully actuated. The faster the desired actuation, the faster the voltage will be applied (usually ramped) and the resulting current (and thus electrical power) will be greatest and vice versa. As a HASEL actuator is a capacitor, as it charges up (and actuates) the current draw exponentially decays to a very low amount. This capacitive charging behavior of the HASEL actuators also implies that if the desired operating frequency or turn-on time is low, the resulting electrical power consumption can be extremely low.
Linear actuator power supplies for HASEL actuators are often custom produced for the specific actuator and operating condition. For a sense of scale of the expected power consumption in your application, the standard HASEL development kit can be considered. This particular portable power supply produces a maximum of 5 watts but often operates at considerably lower power during operation.
The figure below shows the power draw of an actuator (C-5015-06-01-B-AAAB-50-096) that is driven to 8 kV by the portable power supply. Notice that the actuator only draws power when it is being charged to the applied voltage (from time = 0 s to time = 0.1 s). Once at the desired voltage, which corresponds to a specific actuation state, the actuator consumes only milliwatts or less of power to maintain that state.
How efficient is a HASEL Actuator?
As with any electromechanical system, the energy efficiency of a HASEL actuator is highly dependent on the operating conditions, expected use, and other system considerations. Basic academic studies of the electromechanical efficiency (total mechanical work out of actuator/total electrical energy into the actuators) have demonstrated typical values between 15-25% efficiency. Additional considerations, such as switching (often optocoupler or HV MOSFETs, DC-DC converter, and other electrical components) can impact the efficiency of the HASEL actuator. If your application is highly sensitive to efficiency, please reach out to the team at Artimus Robotics to discuss the R&D progress in materials and system design to better evaluate your expected real-world efficiency.
How does the efficiency of a HASEL actuator compare to other actuator technologies?
The power consumption of other technologies greatly depends on the application and specifications of the device. Electric motors (e.g. servo motors) and pneumatic systems can consume anywhere from hundreds of milliwatts to hundreds of watts depending on their size and driving conditions. Electric motors generally have an electromechanical efficiency ranging from 70-90%, whereas pneumatic systems are much lower, ranging from 10-20%, due to inefficiencies associated with pumping a fluid through systems of tubes and valves.
For some applications, the low energy and high efficiency of HASEL actuators can provide both energy and cost savings. Whether your organization has sustainability goals aimed at removing energy-intensive pneumatic systems, or you have a portable requirement and the system will be deployed for long periods of time, the engineers at Artimus Robotics would love to talk with you about how HASEL actuators could help you realize your high efficiency, low electrical energy consumption goals. Please reach out to us at info@artimusrobotics.com.
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 info@artimusrobotics.com.