Fingertip Sensor With Magnet-Prestressed Velostat Structure for Robotic Perception and Exploration

Velostat is a conductive material that can be used as sensing media for robotic tactile perception. However, the performance of the Velostat-based sensors is suppressed by its intrinsic nature of nonlinearity and hysteresis. Furthermore, single tactile perception is inadequate for the execution of tasks in complex robotic applications, where multimodal perception is highly expected to feedback rich interacting information. However, the integration of multiple senses into a unified system remains a challenge. To address these issues, this article proposed a magnet-prestressed structure to enhance the linearity and reduce the hysteresis of Velostat-based sensors. Based on this structure, a novel proximity and tactile sensor was designed for robotic fingertip, which can also discern the proximity of ferromagnetic objects. In scenarios where visual information is limited or unavailable, the sensor’s multimodal sensing capability enables the perception and manipulation of ferromagnetic objects, demonstrating its potential in robotic applications, which was verified by the experiment of detecting, locating, and grasping ferromagnetic objects in sands.