Researchers at Georgia Tech recently unveiled a powerful achievement: a 5-inch-long soft robot that may catapult itself 10 feet into the air – the peak of a basketball hoop – with none legs. The design was inspired by the common-or-garden nematode, a tiny roundworm thinner than a human hair that may jump repeatedly its body length.
By pinching its body into tight kinks, the worm stores elastic energy after which suddenly releases it, flinging itself skyward or backward like an acrobatic gymnast. The engineers mimicked this motion. Their “SoftJM” robot is basically a versatile silicone rod with a stiff carbon-fiber backbone. Depending on the way it bends, it could possibly step forward or backward – regardless that it has no wheels or legs.
In motion, the nematode-inspired robot coils up very similar to an individual squatting, then explosively unbends to leap. A high-speed camera show how the worm curves its head up and kinks in the course of its body to hop backward, then straightens and kinks on the tail to leap forward.
The Georgia Tech team found that these tight bends – normally an issue in hoses or cables – actually let the worm and the robot store way more energy. As one researcher noted, kinked straws or hoses are useless, but a kinked worm acts like a loaded spring. Within the lab, the soft robot reproduced this trick: it “pinches” its middle or tail, tenses up, after which releases in a burst (about one-tenth of a millisecond) to soar into the air.
Soft Robots on the Rise
Soft robotics is a young but rapidly growing field that always takes cues from nature. Unlike rigid metal machines, soft robots are fabricated from flexible materials that may squeeze, stretch and adapt to their surroundings. Early milestones in the sphere include Harvard’s Octobot – an autonomous robot made entirely of silicone and fluid channels, with no rigid parts, inspired by octopus muscles. Since then, engineers have built a menagerie of soppy machines: from worm-like crawlers and jellified grippers to wearable “exo-suits” and rolling vine-like robots.
For instance, Yale researchers created a turtle-inspired soft robot whose legs switch between floppy flippers and firm “land legs” depending on whether it’s swimming or walking. At UCSB, scientists made a vine-like robot that grows toward light using only light-sensitive “skin” – it literally extends itself through narrow spaces like a plant stem. These and other bio-inspired innovations show how soft materials can create recent modes of movement.
Overall, supporters say soft robots can go places traditional robots cannot. The U.S. National Science Foundation notes that adaptive soft machines “explore spaces previously unreachable by traditional robots” – even contained in the human body. Some soft robots have programmable “skins” that change stiffness or color to mix in or grip objects. Engineers are also exploring origami/kirigami techniques, shape-memory polymers, and other tricks so these robots can reconfigure on the fly.
Engineering Flexible Motion
Making a soft robot move like an animal comes with big challenges. Without hard joints or motors, designers must depend on material properties and clever geometry. For instance, Georgia Tech’s jumper had to incorporate a carbon-fiber spine inside its rubbery body to make the spring motion powerful enough. Integrating sensors and control systems can be tricky. As Penn State engineers indicate, traditional electronics are stiff and would freeze a soft robot in place.
To make their tiny crawling rescue robot “smart,” they’d to spread flexible circuits fastidiously across the body so it could still bend. Even finding energy sources is harder: some soft robots use external magnetic fields or pressurized air because carrying a heavy battery would weigh them down.
The nematode-inspired soft robots from Georgia Tech (Photo: Candler Hobbs)
One other hurdle is exploiting the best physics. The nematode-robot team learned that kinks actually help. In a traditional rubber tube, a kink quickly stops flow; but in a soft worm it slow-builds internal pressure, allowing rather more bending before release. By experimenting with simulations and even water-filled balloon models, the researchers showed that their flexible body could hold numerous elastic energy when bent, then unleash it in a single fast hop. The result’s remarkable: from rest the robot can jump 10 feet high, repeatably, by simply flexing its spine. These breakthroughs – finding ways to store and release energy in rubbery materials – are typical of soppy robotics engineering.
Real-World Hoppers and Helpers
What are all these soft robots good for? In principle, they’ll tackle situations too dangerous or awkward for rigid machines. In disaster zones, for example, soft bots can wriggle under rubble or into collapsed buildings to seek out survivors. Penn State showed a prototype magnetically controlled soft crawler that would navigate tight debris and even move through blood-vessel-sized channels.
In medicine, microscopic soft robots could deliver drugs directly within the body. In a single MIT study, a thread-thin soft robot was envisioned to drift through arteries and clear clots, potentially treating strokes without open surgery. Harvard scientists are working on soft wearable exoskeletons too – a light-weight inflatable sleeve that helped ALS patients lift a shoulder, immediately improving their range of motion.
Space agencies are also eyeing soft leapers. Wheels can get stuck on sand or rocks, but a hopping robot could vault over craters and dunes. NASA is even imagining novel jumpers for the Moon and icy moons. In a single concept, a soccer-ball-sized bot called SPARROW would use steam jets (from boiled ice) to hop many miles across Europa or Enceladus. Within the low gravity of those moons, a small jump goes a really great distance – scientists note that a robot’s one-meter leap on Earth could carry it 100 meters on Enceladus. The concept is that dozens of those hoppers could swarm across alien terrain “with complete freedom to travel” where wheeled rovers would stall. Back on Earth, future soft jumpers could assist in search-and-rescue missions by leaping over rivers, mud, or unstable ground that will stop conventional robots.
Soft robots are also finding work in industry and agriculture. NSF points out they might develop into secure helpers on factory floors or on farms, because they comply if a human is in the best way. Researchers have even built soft grippers that lightly pick delicate fruit without bruising it. The pliability of soppy machines means they’ll act in places too small or flexible for rigid devices.
In the long run, experts imagine soft robotics will fundamentally change many fields. From worms to wearable suits to lunar hoppers, this research thread shows how studying tiny creatures can yield big jumps in technology.
