Worms have the ability to move with accuracy and speed without having limbs or bones in general. They have the ability to cross a number of different terrains and find their way among substantial obstacles. The movement ability of earthworms and inchworms inspired scientists at University of Glasgow to create robots of similar shapes and capabilities.
Inherently, worms are soft and flexible to be stretched. This helps them to squeeze through small spaces and make sharp turns. While their movement is simple, it is quite extraordinary knowing how simple these organism are. Interestingly, the body mechanics of worms is very accurate despite fewer number of parts in the body mechanism.
Taking a cue from this, scientists created wiggly, soft roboworms that can stretch nine times of their length. This enables them to squeeze through incredibly tight spaces without damage. Furthermore, the engineering of these robots is such to have the ability of proprioception – a method used by worms to visualize their position in the surrounding.
The construction of such a flexible and stretchable robot is not easy. This involved combining results from previous and exploring the capabilities of embedded flexible electronics. This led to the construction of roboworm each 4.5 cm in length and covered in stretchy plastic called graphite paste and Ecoflex. The stretchy bodies of roboworms have intrinsic strain sensors and permanent magnets, which help them to traverse on metal surfaces.
With stretching of the roboworm, this causes resistance change in the graphite paste detected by embedded sensors. On reaching of resistance to a preset value, this causes contraction in the roboworm to regain shape and prepare for the next move.