Worms don’t have any limbs or bones in general, but move with precision and speed. They are able to cross many different terrains and navigate quite substantial obstacles. This is why scientists at the University of Glasgow were inspired by the movements of inchworms and earthworms and created robots of similar shapes and capabilities.
Inchworm – one of the inspiration givers of new flexible roboworms, which one day may help in mining, disaster relief and other areas. Image credit: Melissa McMasters via Wikimedia (CC BY 2.0)
Worms are soft and stretchy. This helps them squeeze through quite tight spots and make sharp turns. Their movement, while simple, is quite extraordinary, having in mind how simple these organisms are. Their body mechanics are very accurate, while the mechanism itself does not have too many parts. This is why scientists created soft, wiggly roboworms that can also stretch to nine times their own length. This helps them squeeze through incredibly tight areas without taking damage. Furthermore, these robots are engineered to have the ability of proprioception, which is a method worms use to perceive their position in space.
Building such an extremely flexible and stretchable robot is not easy. Engineers built on previous studies exploring capabilities of embedded flexible electronics. Each robot was about 4.5 cm long and is covered in stretchy plastic called Ecoflex and graphite paste. They have intrinsic strain sensors built into their stretchy bodies and permanent magnets, which are there to help them move across metal surfaces. As the body of the worm stretches, resistance in the graphite paste changes, which is detected by the embedded sensors. When the resistance reaches a preset value, the roboworm contracts again, regaining its shape and preparing for the next move.
These robots are able to squeeze themselves through unbelievably tight spots and will be able to navigate themselves very well. This will be very useful in a wide range of applications, such as mining, construction or even in disaster relief. These robots will be able to look for survivors in rubble autonomously. Of course, before any of that is possible, more development needs to be done.
Scientists say that roboworms are a huge step in the development of soft robots. Ravinder Dahiya, lead author of the study, said: “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.”
Flexible robots will be very useful, because they can adapt to their surroundings better and are very tough. However, it will be years until these roboworms can become some kind of useful tool. In any case, lessons learned in studies like this should push us forward in robotics.