HASEL actuators use voltages ranging from 2,000 to 10,000 volts: how can this be safe?
Most people are familiar with “Danger! High Voltage!” signs that are commonly used to identify potentially hazardous electrical equipment, such as grid-scale transformers. While these signs are certainly valid for some electrical equipment that operates at high voltages, they are somewhat misleading and have contributed to a negative connotation regarding high voltage and electrical safety. High voltage is not inherently dangerous; anyone who has rubbed their feet on a carpet for a while and then touched a metal doorknob has experienced a high voltage electrostatic discharge (ESD) firsthand. In fact, such discharges can have voltages ranging from 2,000-15,000 volts, but transfer only a small amount of charge that results in a short duration of current that flows through you. The result is a quick, harmless zap of electricity, which is sometimes not even perceptible. This zap of electricity can damage sensitive electrical equipment, however, and personal electronics (e.g. cell phones, computers, etc.) have built-in protection against ESD.
“It’s important to learn the nuances of electrical safety. High voltage does not always mean high danger, but in some cases it certainly does (e.g. grid-scale transformers, lightning strikes, etc.). There are many factors that contribute to the danger associated with high voltages, but it primarily depends on the amount of current and the duration of the exposure to the current.
In the context of electrical safety around HASEL actuators, the danger from high voltage is minor, since they require very small amounts of current (ranging from microamps to milliamps) to charge. An electrostatic shock from an actuator will cause only momentary discomfort. However, it is always important to practice high voltage safety when using the actuators. A few tips and pointers:
Never touch the actuators or their electrical connections when they are in operation unless the actuator has been specifically designed to come in contact with the human body (e.g. encapsulated and grounded).
Since the actuators are capacitive devices, they can hold a charge even when the power supply is turned off or not used correctly. Always make sure the high voltage (HV) switch is turned off for at least 10 seconds and the actuator is visibly relaxed before turning off the main power switch or handling the actuators.
Ensure the actuators and their electrical connections are a sufficient distance (at least 1 inch) from any electrically conductive surface (e.g. metallic tabletops) or sensitive electronic devices, such as phones and computers.
It is important to note that the electrical safety of the actuators is dependent on the materials used for the actuators, the size and number of actuators, and the driving electronics. Therefore, safety information can change from product to product as some actuators are designed to be safe to touch. Contact Artimus Robotics if you have questions about the safety of a specific actuator product.
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.