There are no superhumans in the real world, but super robots may appear someday. Obviously, we can build robots that are stronger, faster, and better than humans, but do you think there are limits to building robots that are better than humans?
Thanks to continued advances in materials science and soft robotics, scientists are now developing new technologies that will enable future robots to push the boundaries of non-human biology. For example, a research team at the University of Colorado Boulder recently developed a material that yields a soft-his robot that can jump 200 times her own thickness. One of the most amazing leaping grasshoppers on the planet, Grasshopper can only leap into the air up to 20 times her length.
Despite outperforming insects, the researchers behind the rubber-like jumping material say they were inspired by grasshoppers. Much like insects, the material stores a large amount of energy in its area and releases it in bursts while jumping.
Discovered by chance
The rubbery film is composed of liquid crystal elastomer (LCE). This special material consists of a crosslinked polymer network. They exhibit the properties of elastomers (used to make tires, glues and soft robots) and liquid crystals (used to make TV displays, artificial muscles and microbots) and are highly responsive to various external stimuli. Overall, LCE is stronger, more flexible and a better actuator than traditional elastomers.
The lead author of this study, Taylor Hebner, and her colleagues were investigating LCE and its shape-changing ability. I didn’t intend to build a jumping robot at the time, but I did observe an interesting behavior of the LCE. “Just watching the liquid crystal elastomer lay on his hot plate, I wondered why it didn’t form the way I thought it would. ” Hebner said in his news release.
Upon contact with the hot spot, the material first distorted, flipped over, and then suddenly, within the next 6 milliseconds, sprang into the air to a height approximately 200 times its thickness.
Researchers realized that LCE reacts to heat, leading to the development of grasshopper-like materials. While commenting on these findings, Hamed Shahsavan, a materials science expert at the University of Waterloo, who was not involved in the study, told Ars Technica: This study also uses heat to generate the energy required for LCE deformation and jumping. “
What causes the material to jump?
According to the researchers, the grasshopper-like material consists of three elastomer layers and a liquid crystal. When the material is heated, the elastomeric layer begins to shrink, but the shrinkage rate is faster with the top two layers being less stiff than the bottom layer. Meanwhile, the liquid crystal also begins to shrink. These disproportionate changes result in a conical formation near the feet on the underside of the robot’s body.
The robot has four legs attached to the four corner sides. Two short legs in front and two long legs in back. Compared to the short legs, the long hind legs provide a higher point of contact, and the snap-through force lifts the material at the desired angle, according to the researchers.
A large amount of energy is stored in the cone, which leads to mechanical instability of the film. As the LCE heats up further, the conical structure rapidly flips, kicking the material into the air. The study authors said: However, changes in the LCE response and material mechanical properties have been shown to introduce transient instabilities manifesting as snap-through of free-standing films. “
Researchers claim that the configuration of the jumping material can be changed so that it jumps on cooling rather than heating. Additionally, you can easily control the direction in which the material jumps by changing the placement of the legs. Shahsavan suggests that using his LCE like that, he could create a variety of mobile he soft robots and devices.
“By constraining the jumping mechanism shown in this study, there is a large amount of energy output density that can be harvested for the load-bearing capabilities of small soft robots. Jumping is also useful for locomotion of small robots on uneven terrain.” It can be used directly or as an auxiliary mechanism to other locomotion mechanisms such as walking, crawling, and inching.”
LCE was discovered by a chemist named Heino Finkelmann about 42 years ago, but this is probably the first time scientists have recognized LCE’s extraordinary jumping ability. The resulting grasshopper-like material could be a powerful locomotion vehicle for soft robotics.
Science Advances, 2023. DOI: https://doi.org/10.1126/sciadv.ade1320 (About DOI)
Rupendra Brahambhatt is an experienced journalist and filmmaker. He covers science and culture news and has spent the last five years actively working with some of the most innovative news agencies, magazines and media brands operating in different parts of the world.
