A soft magnetoelectric finger for robots' multidirectional tactile perception in non-visual recognition environments

Robotic fingers capable of multidirectional tactile perception are crucial for exploring complex, non-visual environments, yet most existing tactile sensors detect forces only along a single direction. The authors demonstrate a soft magnetoelectric finger (SMF) that achieves self-generated-signal, multidirectional tactile sensing using a flexible Ecoflex sheath with five embedded liquid metal (LM) coils surrounding a magnetized phalangeal “bone.” External forces change magnetic flux through the LM coils, producing distinct induced voltages explained by Maxwell simulations. By analyzing signals from the five coils, the SMF detects forces from varied directions and distinguishes six common objects with different Young’s moduli with 97.46% accuracy. Integrated with a robotic arm, the SMF explores a black box, identifying walls/ground features and object types, highlighting its suitability for non-visual robotic exploration.