Technology is now available in Australia to detect how firmly a robot is touching or holding an object. The development means modern robots can have a human-like sense of touch.
The UK’s Shadow Robot Company is now distributing its compact tactile sensors through Romheld Australia.
Shadow’s Technical Director, Rich Walker said the sensors depend upon an innovative material that the company’s engineers learned about in an industry magazine:
“Shadow developed these tactile sensors in order to give robots a sense of touch equivalent to the human sense of touch. Since we were building robots with human-shaped fingers, we needed them to be in the shape of the human finger. We did a lot of work exploring ways we could make a sensor that would have really good response, but were having lots of trouble. One day, one of our engineers said “This would be really easy if we had some QTC” and pulled out an article in one of the design mags about this material,” Walker told FEN.
QTC is a metal-filled polymer material developed by Peratech in England. The acronym stands for Quantum Tunnelling Composites, which describes what happens when pressure is applied to the material. Whereas in most carbon filled polymers, carbon particles come into contact and build up conduction pathways, in QTCs the metal particles never touch. Rather, they get so close that Quantum Tunnelling is possible — that is, the electron effectively tunnels through the non-conductive barrier. The result is a material with a resistance that varies with applied load.
The Shadow Robot Company realised that if they could make a sensor using this material, it should have really good properties, Walker explained:
“We've spent about two years working out how to make a sensor out of QTC — it’s an interesting material to work with. What we've got is a sensor that is responsive, in each region, to a very light touch, and also to loads up to as hard as we can press. The limits of the sensors are pretty much to do with our ability to make the electronics.”
The sensor is available in two shapes, suitable for a thumb or finger, as well as in two sizes, with 34 or 22 individual tactile elements (tactels). Each tactel is sensitive to loads ranging from 0.1Nto 25N.
The tactels are evenly distributed over the surface of the sensor with the thumb and the finger both having the same number of tactels, but in a slightly different arrangement.
The Shadow Robot Company is anticipating ideas from international robot-users, for how the system might be applied and extended, Walker said.
“The current sensors are highly optimised for the needs of a robot Hand. However, the technology is applicable to almost any area where you need an area made sensitive so you can detect how hard you are touching or holding objects in that area. We are currently looking at ways to interface the sensors to other systems, and are interested in possible applications people have in mind.”
www.shadowrobot.com/hand/overview.shtml
www.romheld.com.au
Add a comment