Inspired by the animal kingdom, using smart polymeric materials, a new generation of robotic tools is beginning to take shape owing to a mix of powerful muscles and sensitive neural receptors.
Octopuses have the most flexible appendages of any creature on the planet. Each of the cephalopod’s eight arms contains roughly two-thirds of the brain’s neurons, allowing them to sense and respond to external conditions with little to no input from the brain. In addition to being supple and powerful, it can bend, twist, lengthen, and shorten in a variety of ways to generate a variety of locomotions.
The octopus’s highly dexterous limbs have been used as inspiration for the construction of soft robots. Moreover, the capacity to respond and adapt to local conditions without needing a central controller has fascinated the minds of robotics developers.
Recently, a team of researchers from The Ohio State University and the Georgia Institute of Technology has developed a robot arm that moves like an octopus tentacle without the necessity for a motor. The new robotic arm’s flexibility comes from a few important characteristics, such as magnetic-field-driven motions rather than motors, origami-inspired panels, and a soft exoskeleton.
The researchers employed a segmented method to create a limb that might imitate an octopus arm. Individual segments of hexagonal-shaped, soft dual silicon plates with embedded magnetic particles were used to construct the arm – where the plates were joined together using Kresling origami-inspired slanted plastic panels. Kresling is a style of origami that twists to lengthen and contract. Made using buckling thin shell cylinders, it is an excellent building block for the origami robotic arm because of its inherent multimodal deformation capacity, which allows for deployment, folding, and bending.
Following that, the plates were used to join the segments. The arm was then put in a magnetic field that could be controlled. Since each section had its own magnetic particles, the researchers could control each one separately by altering the magnetic field’s characteristics. This allowed the robot arm to rotate 360 degrees as well as vary its length by twisting the segments together in a concertina-like fashion or expanding to make them longer. According to the researchers, the octopus tentacle design leaves much room for customization, which includes the number of segments, plate size and the degree of bendability.
For the testing phase, the researchers created a three-dimensional magnetic field surrounding the arm using electromagnetic coils. They could produce torque by simply changing the direction of the magnetic field surrounding the arm, which would drive the torque and deformation of the individual origami parts. Researchers were also able to fine-tune the motions by controlling each section of the arm separately.
The noncontact actuation of the Kresling robotic arm makes it a unique mechanism for applications that need synergistic robotic movements for navigation, sensing, and interfacing with objects in restricted settings or confined access. The team affirms that miniaturized medical equipment, like tubes and catheters, can be produced using small-scale Kresling robotic arms combined with endoscopy, intubation, and catheterization operations by employing object manipulation and motion under remote control. Even in surgeries requiring treatment delivery, origami robots can allow the material to ‘open’ as it arrives at the spot, unfurling the treatment along with it and applying it to the body part that requires it. Hence, the octopus robotic arm trades strength with flexibility.
While a conventional robotic arm will need a number of motors that will enable it to have a higher degree of freedom, this octopus robotic arm achieves that only using magnetic fields. These results concerning the control and function of the octopus robotic arm offer a lot of potential for creating self-driving soft robots for healthcare and other industries.