17-03-2025
Artificial muscles for robots brought closer to reality with 3D-printed actuators
Swedish researchers have developed a breakthrough 3D printing method to create soft actuators.
These dielectric elastic actuators (DEA) are made from silicone-based materials, combining conductive electrodes with non-conductive dielectrics in interlocking layers.
According to the team at Swiss Federal Laboratories for Materials Science and Technology (EMPA), the innovation enables the efficient production of complex, flexible components, advancing soft robotics and smart materials.
"One day, these could be used in medicine or robotics – and anywhere else where things need to move at the touch of a button, said researchers in a statement.
Artificial muscles could one day assist workers, aid mobility, or replace damaged tissue. However, replicating real muscle function remains a challenge. To match biological muscles, artificial versions must be powerful, elastic, and soft.
They are fundamentally dependent on actuators, which are parts that translate electrical information into motion. Although actuators are frequently found in automobile engines, industrial systems, and residences, their conventional designs are stiff and lack the flexibility of actual muscles.
To bridge this gap and bring artificial muscles closer to practical uses in robotics, prosthetics, and assistive technologies, researchers say new materials and manufacturing processes are needed to produce actuators that move naturally.
An important advancement has been made by researchers at Empa's Laboratory for Functional Polymers, who have created a technique for 3D printing soft actuators.
According to the team, these DEAs are composed of interlocking layers of two silicone-based materials: a conductive electrode and a non-conductive dielectric. When voltage is applied, the actuator contracts like a muscle and relaxes when the voltage is removed.
Printing such structures is complex, as the materials must remain distinct yet adhere together. They must also be soft enough for electrical activation while meeting 3D printing requirements—liquefying under pressure for extrusion but solidifying quickly to maintain shape, balancing conflicting properties.
Researchers from EMPA, in collaboration with ETH Zurich, developed a breakthrough method for 3D printing soft actuators, overcoming many conflicting material properties. Using specially formulated inks and a custom-designed nozzle, they successfully created functional artificial muscles.
The effort is a component of the Manufhaptics project, which intends to create a glove that simulates resistance while gripping to enable users to feel virtual things.
These soft actuators have several uses outside of virtual reality. They are a possible substitute for conventional actuators in automobiles, industrial machinery, and robots since they are small, quiet, and incredibly flexible in shape. According to the team, their adaptability and customization create opportunities for medical applications like prosthetics or assistive technology.
The recently created method increases the possibility of soft, responsive materials by printing long, elastic threads in addition to intricate structures. These developments may eventually result in actuators that closely resemble the way muscles work naturally, which would advance wearable technologies, robotics, and medical treatments.
"If we manage to make them just a little thinner, we can get pretty close to how real muscle fibers work," said Dorina Opris, who leads the research group Functional Polymeric Materials at Empa, in a statement.
The possibility of printing an entire heart from these fibers may one day become a reality, but significant challenges remain.
