A unified mechanics model of direct-ink-writing printed flexible sensor benefits the accurate force control of soft manipulator

Abstract

High-precision strain feedback is crucial for both monitoring and control of structure-sensing assembly, but remains a big challenge especially for soft components due to the transferring loss and reinforcement effect. Here we propose a closed-loop solution from unified mechanics model for sensor-assembly design to hybrid additive manufacturing of structure-sensing component. As a result, the strains of soft component from surface to interior are detected with high accuracy, thereby removing the barriers for the strain-based control. Benefit from the proposed mechanics model, the high-precision strains at the fingertips with printed sensors are detected with a reduction for measurement error from 37% to 7%. Consequently, the grip postures can be adjusted according to the feedback strain to accurately control the pinching forces, which successfully pick up fragile objects without damage. This mechanics-model-based strain-feedback control strategy provides insight for achieving intelligent soft equipment with the demand of high-precision control of postures and forces.