A group of researchers from Italy's Sant'Anna School of Advanced Studies created a robotic arm that bends, stretches, and squeezes through cluttered environments. Inspired by the eight arms of an octopus, the device allows surgeons to easily access remote, confined regions of the body and, once there, manipulate soft organs without damaging them.

The octopus has no rigid structures and can thus adapt the shape of its body to its environment. The eight highly flexible and long arms can twist, change their length, or bend in any direction at any point along the arm. The researchers' device has similar flexibility, with its ability to transform from a bending instrument into a stiff and rigid one.

The engineers believe that the technology could reduce the number of instruments – and therefore entry incisions – necessary in surgical operations. Part of the arm can be used to manipulate organs while another part of the arm operates.

To achieve this effect in the robotic arm, the Sant'Anna team constructed two interconnecting identical modules. Each module is made to move by the inflation of three equally spaced cylindrical chambers. By alternating and combining the inflation of the three chambers, the module can be made to bend and stretch in various directions.

The stiffness of the two modules can also be controlled by exploiting a "granular jamming phenomenon" in which a flexible membrane inside the module is filled with a granular media. When a vacuum is applied to the membrane, its density increases and the whole membrane becomes rigid.