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What is a Good Replacement for Piezoelectric stack actuators?

A ceramic that expands or contracts when an electrical charge is applied is called a piezo element. This element generates bending or linear movement and force. Piezo elements can be layered on top of each other, creating a stacked piezoelectric actuator. Since piezoelectric actuators produce very small movements, stacking them in modular layers is a way to get more movement. However, the common strain ranges of piezos are very limited, usually 0.1% to 0.15% actuation strain. Even when stacked, piezos can usually only provide less than one millimeter of stroke. Piezoelectric actuators are used in industrial automation, automotive, defense, and more. Common applications for piezo actuators include precise positioning devices, electrical switches, micro-pumps, valves for liquids and pneumatic systems, inkjet printers, and anti-vibration devices. However, since piezoelectric stack actuators contain lead, a substance banned by the RoHS directive in the EU, many of these applications are searching for alternatives.

Stacked piezoelectric actuators are a common actuation solution, but emerging technologies are offering alternatives for small linear actuators. One example is HASEL actuators, which have many similarities to piezoelectric actuators, but they also have some marked differences. With HASEL actuation technology, an electrostatic force is applied to a flexible polymer pouch containing a dielectric liquid, prompting a soft structure shape change. HASEL actuation technology enables smart, versatile, and compact motion solutions. HASEL technology offers analog (proportional) control and gets much higher actuation strain (10% for contracting designs and 100% for expanding designs) than piezos, making HASEL actuators a better actuation solution for applications requiring 1-10 millimeters of stroke. While HASEL actuators are well suited for applications in search of small linear actuators, they can also be scaled to centimeter-scale or greater making these actuators appropriate for more than just small scale actuation. HASEL actuators do not contain lead or any other substance banned by the RoHS directive, and HASEL actuators are made from very inexpensive materials, making HASEL a good replacement for stacked piezoelectric actuators.

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

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