Harvard researchers have developed a tactile sensor, based on the barometric principle, which can turn a robotic hand into a dextrous manipulator so as to enable the robot to identify objects it touches and use them appropriately.

TakkTile recreates the sense of touch by placing a barometer chip in the palm of a robot hand

Much research is currently going into improving and refining robots’ ability to recognise objects, with the aim of making them more autonomous. One recent noteworthy example is a project run by researchers at Stanford and Carnegie Mellon Universities in the United States, who have developed an algorithm that enables robots to identify objects around them and classify them in terms of potential movement. Now researchers at the Harvard School of Engineering and Applied Sciences (SEAS) have developed a sensor called TakkTile, which enables robots to recognise objects they hold in their ‘hands’. TakkTile is based on a common existing device – a tiny barometer, which senses air pressure – plus an added a layer of vacuum-sealed rubber capable of protecting the chip from excess direct pressure. The basic principle is that the system uses atmospheric pressure to determine the weight of a given object.

New milestone in robot autonomy

TakkTile chips can survive a hammer blow or a strike from a baseball bat and yet are at the same time sensitive enough to detect a very slight touch. The patented process relies on standard methods used in printed circuit board manufacture. The tiny barometers are similar to those widely used in cell phones and GPS units, which can gauge altitude. Back in 2011, researchers at the Technical University of Munich, Germany, were already working on a tactile perception project. The Munich team developed an artificial skin for robots to help them navigate in their environments. TakkTile goes further however. Adding the barometric technology to a robot’s mechanical hand enables it to figure out what it's touching. It can take hold of a balloon without bursting it or pick up a key and unlock a door.

Looking to market the technology

“Despite decades of research, tactile sensing hasn’t moved into general use because it’s been expensive and fragile,” explains SEAS graduate student and TakkTile co-creator Leif Jentoft, adding: “It normally costs about $16,000 to put tactile sensing on a research robot hand (…) TakkTile changes that because it's based on much simpler and cheaper fabrication methods.” Beyond robotics, the TakkTile sensor could be used in a range of electronic devices. A toy manufacturer could for instance make a stuffed puppy that responds to being patted; a medical device designer could create a laparoscopic gripper that's gentle enough to tease apart tissue during surgery. The researchers are now pursuing commercial opportunities and are planning to license the technology to companies interested in manufacturing prefabricated sensors or integrating TakkTile sensing into products in addition to robots, such as consumer devices and industrial equipment.

By Pauline Trassard