We, human beings, are able to grab objects with our hand thanks to the thumb that serves as a clamp. It brings precision and strength in grasping things more easily. However, there are several animals in nature, for instance, octopus, that can be more effective in this matter and hold objects with limbs such as tentacles. The hundreds of suckers that cover octopus’ arms can form strong seals even on rough surfaces underwater.
Inspired by the octopus and its ability to grasp and manipulate objects of different sizes, a group of researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Beihang University has developed a robotic arm with an end similar to a tentacle. This octopus-inspired soft robotic arm (tentacle bot) can grip, move, and manipulate a wide range of objects.
“Most previous research on octopus-inspired robots focused either on mimicking the suction or the movement of the arm, but not both,” said August Domel, a Ph.D. graduate of Harvard and co-first author of the paper published in Soft Robotics. “Our research is the first to quantify the tapering angles of the arms and the combined functions of bending and suction, which allows for a single small gripper to be used for a wide range of objects that would otherwise require the use of multiple grippers.”
The tentacle bot is controlled with two valves, one to apply pressure for bending the arm and one for a vacuum that engages the suckers. By changing the pressure and vacuum, the arm can attach to any object, wrap around it, carry it, and release it. Besides, the tapered design of the octopus arm allows it to fit into tight places.
As you can see in the video, the robotic arm is able to sneak through any place, and once the object is found, it begins to wrap around it. At the same time, its suction cups give the gripper a firm grasp on objects of all shapes, sizes, and textures. In testing, the arm was able to pick up many different objects, including thin plastic sheets, coffee mugs, test tubes, eggs, and even live crabs.
It is not the first robotic tentacle we have seen that uses such a suction system, but this one, according to the creators, is unique in its dual activation approach: that is, it is capable of twisting in addition to applying pressure on the surface of an object in order to hold it and prevent it from falling.