Tactile robots

German researchers are developing an underwater robot that could perform repairs on submerged cables without the aid of a human.


A team from two research centres in Bremen are developing a special ‘printed sensor’ that will give robots a ‘sense of touch’ and help them detect their undersea environment autonomously.


‘One component in this tactile capability is a strain gauge,’ said Marcus Maiwald, project manager at the Fraunhofer Institute for Manufacturing Technology and Applied Materials Research (IFAM), which is working with the German Research Centre for Artificial Intelligence on the robot.


‘If the robot encounters an obstacle, the strain gauge is distorted and the electrical resistance changes,’ he added. ‘The special feature of our strain gauge is that it is not glued but printed on, which means we can apply the sensor to curved surfaces of the robot.’


The single printed strip is just 10 micrometres wide and about half the width of a human hair. As a result, the strain gauges can be applied close to each other and the robot can identify precisely where it is touching an obstacle. The sensor is protected from the salt water by encapsulation.


To produce the strain gauges, the research scientists atomise a solution with nanoparticles to create an aerosol. A software system guides the aerosol stream to the right position.


The researchers are presenting a demonstration octopus-shaped underwater robot fitted with a printed sensor at the Sensor and Test trade show from 26 to 28 May in Nuremberg.