Have you ever wondered why robots can’t walk and move as smoothly as we do? Some robots run, jump, and dance more efficiently than humans. However, the movement of its body also appears mechanical. The reason for this is a lack of bone.
Unlike humans and animals, robots do not have real bones or flexible tissues that connect them. It features artificial links and joints made from materials such as carbon fiber and metal tubing. These internal structures allow the robot to move, grasp objects, and maintain different postures, according to Robert Katzschmann, a robotics professor at ETH Zurich. However, the robot’s body is not as flexible, agile, and soft as the human body because its links and joints are made of hard materials. This is what makes their body movements so stiff.
However, it may not be necessary to stay stiff for long. A team of researchers from the Swiss Federal Institute of Technology (ETH) Zurich and US-based startup Inkvit has created the world’s first robotic hand in 3D with an internal structure made of human-like bones, ligaments and tendons. I discovered a way to print. What makes this hand even more special is that it was printed using a completely new 3D inkjet deposition method called Vision Control Jetting (VCJ).
3D printing vs. robots
Currently, 3D printed robots are typically made using fast-curing polyacrylate. These polymers are durable and solidify quickly during deposition. However, “mechanical flattening is required for each printed layer” to avoid irregularities. [the process of smoothing an uneven surface by using mechanical force]This limits the level of softness and type of material chemistry that can be used,” the researchers said. Note. For this reason, standard 3D printed robots have low elasticity and are limited in shape and material.
The printed material solidifies quickly, so scientists don’t have time to make modifications to the various layers. Adopt separate manufacturing steps Assembly to create different components of a single robot. Once each part is printed, these various parts are assembled and thoroughly tested, making this process time-consuming and tedious.
Here, the proposed VCJ technique can make a big difference. This 3D printing process uses thiolene polymers, which are soft and slow to cure. “They have very good elastic properties and recover after bending much faster than polyacrylate.” Said Katzschmann is one of the authors of a new paper describing the new technique.
Rethinking 3D printing for robots
Along with a 3D printer, the VCJ system is equipped with a 3D laser scanner that visually inspects the surface roughness of each layer as it is deposited. “This visual inspection ensures that the printing process is completely non-contact, allowing us to deposit a wider range of polymers. For example, we have printed using thiol-based polymers that are resistant to UV light and moisture.” Because you can create structures,” Katzschmann told Ars Technica.
After scanning, no mechanical planarization of the deposited layer is performed. Instead, the next layer is printed to compensate for any irregularities in the previous layer. “The feedback mechanism compensates for these irregularities when printing the next layer by calculating in real time and pinpoint the necessary adjustments to the amount of material printed.” Said Wojciech Matusik is one of the study authors and a computer science professor at MIT.
Furthermore, the researchers claim that this closed-loop control system allows them to print the complete structure of the robot at once. “Our robot hand can be printed in one go and does not need to be assembled. This greatly speeds up the engineering design process and allows us to create functional, permanent prototypes directly from ideas. Intermediate tooling and assembly can be avoided,” added Katzschmann.
Researchers have successfully used VCJ technology to print a robotic hand with an internal structure similar to that of a human hand. Equipped with a touchpad and pressure sensors, this robotic hand has 19 tendon-like structures that allow it to move its wrists and fingers (in humans, tendons are fibrous connective tissues that connect bones and muscles). Equipped with: Hands can sense touch, grab objects, and stop their fingers when they touch something. (Researchers used his MRI data from a real human hand to model its structure.)
Future of VCJ
In addition to the hands, they also printed a robot heart, a six-legged robot, and a metamaterial that can absorb vibrations from the surrounding environment. The researchers believe that all of these robots are hybrid soft-rigid systems (both soft and hard materials) that can outperform hard robots in terms of flexibility and overcome design and scale-related issues faced by soft robots. It is suggested that the robot behaves like a robot created by the robot.
Because soft robots are made of flexible materials such as fluids and elastomers, it is difficult for scientists to maintain their shape and strength on large scales due to material effects. have a hard time maintaining their physical properties and structural integrity; Furthermore, controlling and powering centimeter or millimeter scale soft robots is much easier. This is why it is miniaturized. VCJ, on the other hand, has the potential to create scalable soft-rigid hybrid robots.
“Eventually, we expect VCJ to replace all contact-based inkjet printing methods. With VCJ, we can begin manufacturing functional parts for robotics, medical implants, and a variety of other industries. “The high resolution, suitable material properties and their long lifetime make prints from VCJ systems very useful for both research and commercial applications,” Katzschmann told Ars Technica.
Nature, 2023. DOI: 10.1038/s41586-023-06684-3 (About DOI)
Rupendra Brahanbat is an experienced journalist and filmmaker. He covers science and culture news and for the past five years has actively collaborated with the most innovative news agencies, magazines and media operating in different parts of the world.