Scientists have created a 4D-printed soft robot capable of self-assembly when it is heated. Through this process, the robot, once assembled, can be given challenging tasks to perform. Such tasks include rolling uphill or navigating an uneven and unpredictable landscape.
So far, a strange-looking tube-shaped prototype has been created. Describing the appearance, lead researcher, Wei Feng (Tianjin University in China) declares that the robot is much: “Like an insect with antennae, the robot can surmount a small obstacle. But when the obstacle is too high, it will turn back…The whole process is spontaneous without human interference or control.”
The process with constructing and assembling the robot commences with as a flat, rectangular sheet fashioned from a 3D-printed liquid crystal elastomer. As the surface beneath it is heated, the robot begins to twist up and a shape begins to form. The shape is as a tubule resembling a spring. The change in shape under external stimulation adds time as a fourth dimension to the printing process, hence the additive printing process is referred to as ‘4D’.
4D printing is the process through which a 3D printed object transforms itself into another structure over the influence of external energy input as temperature, light or other environmental stimuli.
The robot, now formed, contacts with the hot surface. This induces a strain in the material, and the reaction causes the robot to roll in one direction. Provided the heat is sufficient, the robot can climb up a 20° incline or carry a load 40 times its own weight.
This video shows the robots in operation.
The properties of the robot are due to liquid crystal elastomers. These are captured into samples of various shapes through 4D printing. The robot process was developed by stimulating various samples with light, heat, and electricity. By observing the different responses, the Chinese scientists found many interesting driving phenomena besides deformation, and this will enable various movements to be controlled going forwards.
In terms of practical use, such soft robots can be used to operate in small, confined places like in a pipe or under extreme conditions.
The research appears in the journal Matter, titled “4D-printed untethered self-propelling soft robot with tactile perception: Rolling, racing, and exploring.”
