According to recent research conducted by North Carolina State University, technological developments have made it possible to control the deformation and motion of soft robots with 3D-printed miniature soft hydraulic actuators. These actuators are capable of managing robots that are less than a millimeter thick. Remarkably, they are also compatible with shape memory materials, which lets users repeatedly lock the robots into any desired shape and revert to their original form when necessary.

"Soft robotics holds promise for many applications, however, it's challenging to design its driving actuators, especially on a small scale," explains Jie Yin, the corresponding author of the paper on this technique. He is an associate professor of mechanical and aerospace engineering at North Carolina State University. "Our approach leverages commercially available multi-material 3D printing technologies along with shape memory polymers to create soft actuators on a microscale. This allows us to control very small soft robots with a level of precision and delicacy previously unachievable."

These progressive robots consist of two layers. The first layer incorporates a pattern of microfluidic channels, essentially small tubes running through the material, in a flexible polymer, created using 3D printing technologies. The second layer is a flexible shape memory polymer. All things considered, the soft robot is only 0.8 millimeters thick.

By introducing fluid into the channels, users can create hydraulic pressure that forces the soft robot to move and change shape. The pattern of the channels can control both the movement and the alteration of the robot's shape. Users could 'freeze' the robots shape using moderate heat and let it cool to prevent reverting. To return the design to its original configuration, users can re-apply the heat after pumping out the liquid, and the robot relaxes back.

Yinding Chi, the co-lead author of the paper and a former Ph.D. student at North Carolina State, brings up a key factor. "You need the memory shape layer to be thin enough to bend when actuator pressure is applied, yet thick enough to hold its shape even after pressure removal."

In a demonstration, the researchers created a soft robot "gripper", capable of picking up small objects. By applying hydraulic pressure, the gripper was able to pinch closed on an object. Further application of heat helped fix the gripper in its closed state, even after the pressure was released. The gripper then transported the object into a new position. Heat application again caused the gripper to let go of the object.

"The robotics movement isn't limited to a gripper that pinches either," add Haitao Qing, the paper's other co-lead author and a Ph.D. student at North Carolina State. They've also showcased a gripper inspired by vines in nature. These grippers swiftly wrap around and clasp an object tightly, providing a secure grip.

This breakthrough technique is heralded as a proof-of-concept. The team is eagerly looking at the potential applications for this class of miniature soft actuators, particularly concerning small-scale soft robots, shape-shifting machines, and biomedical engineering.

Disclaimer: The above article was written with the assistance of AI. The original sources can be found on ScienceDaily.