Morphological and Material Programability of a Hall-Effect Based Soft Tactile Sensors

The different receptors in human skin show not only diversity in the stimuli to which they respond, but also variable sensitivity and directionality. This is often determined by their location or morphology, and can play an important role in filtering or amplifying the stimuli applied to the skin. We require similar capabilities for ‘programming’ the response of soft sensors, such that their responsivity can be varied for the specific task they are performing. We introduce a novel approach that employs hall-effect sensors, with magnets embedded in custom designed soft filters. By modifying the material properties and introducing morphological features into these filters, we mechanically tune the sensor response to normal and shear force. This embodied tuning allows sensors to be adapted to specific tasks without altering robot control policies. We demonstrate the concept through a number of exemplar tasks that leverage amplification, filtering or reduction in sensor signals. This approach provides a scalable means of programming the spatial resolution and directionality of sensor sensors, contributing to more capable sensor-motor control for robots.