Researchers at North Carolina State University have developed miniature soft hydraulic actuators to control soft robots under a millimeter thick. These actuators, made using 3D printing and shape memory polymers, can lock and release robots into desired shapes with precision, enhancing their functionality.
The actuators consist of two layers: a flexible polymer with microfluidic channels and a flexible shape memory polymer. By pumping fluid into the channels, hydraulic pressure changes the robot’s shape. Heat can lock the robot into this new shape, even after removing the fluid. This design provides exceptional control over the robot’s motion and deformation.
Key to this system is balancing the thickness of the shape memory layer. It must be thin enough to bend under pressure but thick enough to hold its shape after the pressure is removed. The researchers demonstrated this with a soft robot “gripper” that picks up and transports objects by locking and unlocking its shape using heat.
These thin robots heat up to 64°C quickly and cool down rapidly, allowing shape changes within two minutes. The technique also includes nature-inspired designs like a vine-like gripper for secure grasps. The ability to quickly and easily change shapes makes these actuators versatile for various applications.
This proof-of-concept shows the potential for miniature actuators in small-scale robotics, shape-shifting devices, and biomedical applications. The ability to control the motion and shape of soft robots with such precision opens up new possibilities in areas where delicate and adaptable movements are required.
Source: scienmag.com