Tactile sensing is an important component to make robotic end effectors more versatile and adaptive. As robots move into the human environment they need to handle a broad range of objects and physically interact with people calling for more resourceful grippers. However, creating an artificial sense of touch has proven more difficult than simulating hearing or seeing. But now researchers have created a tactile sensing system they say is as sensitive as the human fingertip.

For their sensing system the team of researchers of the Georgia Institute of Technology created a new type of transistor that harnesses the piezoelectric effect of converting mechanical force into an electrical charge. The nanoscale transistors can be placed in a densely packed configuration and each can send an individual controlling signal. Pressure changes, even on a tiny area, result in multiple signals being sent to the robot’s AI core, thus simulating the human sense of touch.

The transistors –named taxels by the Georgia Tech team- are made from nanowires of the semiconducting material zinc oxide with piezoelectric properties. There are 1500 vertically placed nanowires, each having a diameter of between 500 and 600 nanometers, in one taxel. The taxels are arrayed in squares of 92 by 92 yielding a density of 234 pixels per inch and are capable of detecting pressure changes as low as 10 kilopascals.

Interestingly, the taxels are two-terminal transistors. Instead of the traditional third terminal controlling the flow of current, the flow is controlled by the electrical charge generated by mechanical force applied to the nanowires.

Besides robotics taxels could also be applied in other fields the researchers suggest. It could help people with prosthetics regain a sense of touch and improve touchscreen human computer interfacing.

The findings were published in the April 25 issue of Science [Paywalled].

Via: Gatech.edu

Image: Georgia Institute of Technology