Engineers from the University of Glasgow‘s James Watt School of Engineering have developed super-stretchy wormlike robots that could be used in industry and artificial limbs.
The way the soft “roboworms” move was inspired by the movements of earthworms and inchworms. Impressively, these roboworms can stretch nine times their own length and are capable of a form of proprioception (sometimes described as the “sixth sense”). Proprioception is how biological organisms such as worms perceive their position in space. That ability (never demonstrated before in soft robotics) allows the robot worms to squeeze into tight areas that rigid robots cannot reach.
The Glasgow team hopes that the breakthrough could lead to a new generation of soft robots that can autonomously explore hard-to-reach areas, which could be used in construction and mining or disaster relief to hunt for survivors trapped in the wreckage.
Artificial Limbs
The new technology could also be used to create more lifelike prosthetics or equip robots with the ability to lift irregularly shaped heavy objects by wrapping around them. The possibilities are endless.
Professor Ravinder Dahiya, who leads the Bendable Electronics and Sensing Technologies (Best) group, which developed the system, said, “Proprioception is a vital characteristic of many forms of biological life, and scientists have long been inspired to try and develop engineered systems that mimic this ability.”
Prof. Dahiya explained, “Our bioinspired robots are a step towards creating soft, flexible robot systems capable of the infinite directions of movement that nature has created in inchworms and earthworms. The ability of soft robots like these to adapt to their surroundings through seamlessly embedded stretchable sensors could help autonomous robots more effectively navigate through even the most challenging environments.”
Unique Sensors
These 4.5 cm-long wormlike robots have intrinsic strain sensors built into them and are covered in “skin” made from a flexible plastic dubbed Ecoflex and a graphite paste made by the team. The sensors in their skin measure the electrical resistance of the graphite paste, allowing them to “sense” their movements concerning their bodies. The paste changes as the robots’ bodies expand.
The roboworms can move along a metal surface due to tiny permanent magnets attached at either end of the robots’ tubular bodies. Once the resistance reaches a pre-set maximum rate, the body of the worm contracts again, moving it forward, just like a worm.
The Glasgow team published their findings on September 1, 2021, in Advanced Intelligent Systems. Thanks to funding from the European Commission and the Engineering and Physical Sciences Research Council, this research was possible. Related non-contact sensing is advancing too—a new electric eel-inspired sensor lets robots feel objects without touching them.
Watch the worm-like bot in action in the video below.
Other Robots
Another soft tubular robot is the snake-inspired soft robot, developed by engineers at Georgia Tech and the University of California, Santa Barbara. The snake-like bot uses various methods to dig sand and soil successfully. Robots are excellent explorers of sea, land, sky, and space, but one of the most challenging environments to navigate is through the ground. This is because even granular materials like sand have far more resistance than water and air.
The soft robot moves by growing from its tip like a vine. This feature is handy for underground adventures. Since the tip is the only moving part, friction is much lower than if more movement is involved. Attached to the growing end of the robot is a device that blows air frontward, pushing sand away and clearing the path so that the robot can move more efficiently.
The robot can move dry granular substances reasonably easily. On its underground journey, it can avoid obstacles by twisting and turning like a serpent, ascending to the other side. The engineers envision the bot gathering soil samples or installing underground pipelines with ease.
Over recent years, we have seen some exciting robots inspired by the animal kingdom. For example, in 2019, Pliant Energy Systems unveiled Velox—a robot, drone, and generator hybrid that charges itself as it moves. Velox can cover nearly every type of terrain on land and make its way through the water, transitioning seamlessly between the two different environments. Velox is unique. For one, it has no legs. Yet, it can crawl and swim. Its creepy and graceful mobility comes from a pair of undulating fins designed to harness the power of the ocean.
