Durable touch sensors developed for cobot applications

Research into developing robots with a sense of touch has taken a further step, with the development of a new form of tactile sensors.

The researchers, from the Queensland University of Technology (QUT) and the University of Queensland, have used nanometre-thin films of organic LEDs (OLED) and organic photodiodes (OPD), which measure soft touch.

While robots with the ability to walk, see, talk, hear and smell, have been manufactured already, developing robots with a sense of touch has eluded researchers and manufacturers.

Touch, however, is essential for the effective manipulation of objects, and for regulating the amount of force applied to an object, to avoid damaging the device the robot is handling.

With a more effective sense of touch, robots could be used in scenarios where they interact with soft, fragile or deformable objects.

To date, the barrier to robotic touch has been the electronics required to translate force into an electronic signal.

In other weighing or pressure sensors, such as scales, piezoelectric transducers are used to turn force into electricity. In these devices, there is a relative slow response time to the force, making them unsuitable for adaptive technologies such as robotics.

Another barrier has been developing touch sensors that can be used in wet environments, with phone and computer touch screens unable to be used when wet.

With a greater need for touch in medical robotics applications, such as restoring touch to those with skin damage or prosthetics, a solution to the issue of touch has been sought by researchers in the field of robotics globally.

The solution from the researchers in Queensland is to manufacture a tiny, opaque and flexible dome above the OLED pixels. When undisturbed, the light emitted by the central pixel reaches the other OLED sensors evenly. When the surface is depressed, light reaches the pixels unevenly. When the combined response from numerous domes is calculated, the force being applied to the domes can be estimated.

The researchers hope that this discovery will lead to robots that can have full body sensing in the air, when wet or in extreme circumstances, under water.