Micro-electronic solutions provider Melexis has developed a fully integrated tactile sensor to give robot hands and grippers a sense of touch.
Tactaxis is designed to be compact, soft and provide the 3D force vector acting on its surface, enabling robotic hands to perform delicate operations such as fruit picking. With the technology now successfully implemented into a functioning prototype.
This prototype features multiple 3D magnetometer pixels, using Melexis’ Triaxis technology. The sensor is accompanied by a magnet which is embedded into an elastomer material. This presents a soft contact interface, emulating the attributes of human skin.
According to Melexia, the arrangement offers high sensitivity so that detection of even small amounts of force will generate a response. The achieved force resolution is 2.7 mN which is enough to distinguish weight change of a fraction of a gram (~ 0.3 gram).
Furthermore, the Tactaxis prototype is compact, with dimensions of just 5mm x 5mm x 5mm, and is therefore suitable for tight spaces.
The gradiometric approach makes the sensor immune to magnetic stray fields, the team said, which prevents potential measurement errors. It is also robust enough to cope with harsh conditions including temperature variations.
Unlike competing optically-based tactile sensors, Tactaxis is built to be completely integrated. It will be possible to produce high volumes of factory-calibrated sensors.
“Robots need the sense of touch to manipulate fragile objects. For such applications, we have developed a novel magnetic sensor to accurately measure the contact force—while being robust against disturbances,” said Gael Close, global innovation manager at Melexis.
“By exploiting the capabilities of our Triaxis magnetic sensor technology, we have made a significant step forward in robot tactile sensors, providing a rugged and competitive multi-axis sensing solution. We will now use the Tactaxis prototype as the foundation for further development work.”
A white paper giving details on the Melexis 3D magnetic force sensor prototype has been published by IEEE (Institute of Electrical and Electronics Engineers).
