The German plastics engineering specialist igus believes that it has created a new market with a system that allows robots to be assembled quickly and relatively cheaply. Its modular robolink system, unveiled at the recent Hannover Fair, is based on a plastic “skeleton” with joints controlled by cable tension, in a similar way to human bones and tendons.

Until now, robot developers have had to assemble complex custom systems from numerous individual components. “During the development of humanoid robots, we spend an enormous amount of time on the mechanisms,” explains Dr Rudolf Bannasch, managing director of Berlin-based robotics specialist EvoLogics, who came up with the idea for the robolink system. “We had been dreaming of a straightforward, modular system for quite some time.”

The system consists of drive and control units, and jointed limbs of different types and sizes which can be assembled into a variety of configurations, from simple robotic arms to four-legged creatures. Developers can choose whether they want to use pneumatic, electrical or hydraulic drives.

A key goal for igus’ developers was to keep the moving mass as low as possible, allowing the actuators to be separated from tools such as grippers, hands and suction cups. The jointed arms are made of carbon-fibre reinforced plastic and other lightweight materials, and incorporate ducts for control cables.

The skeletal parts are controlled by sheathed cables that transfer tensile forces like human tendons. The cable pulls are routed from one joint to the next and just four cables are needed for each joint to rotate and swivel freely. The lightweight, lubricant-free synthetic-fibre cables are said to be stretch-free and extremely strong. They are resistant to chemicals and abrasion.

For more Hannover Fair news, see our in-depth report.