Abstract

Soft robotic grippers offer significant advantages over their rigid counterparts in handling fragile, irregularly shaped objects. However, their widespread adoption is often limited by complex, multi-part fabrication processes and the difficulty of integrating sensing directly into the soft structure. This paper presents the design, fabrication and characterization of a novel, fully monolithic and sensorized soft robotic gripper fabricated in a single print job using Multi-Material PolyJet Additive Manufacturing. The gripper features four pneumatically actuated fingers, each with a bio-inspired, multi-chambered PneuNet (Pneumatic Network) structure. A rigid internal skeleton, printed from a stiff photopolymer, is encapsulated within a soft, elastomeric matrix to constrain deformation and enhance grip force. Crucially, fluidic capacitive sensors are co-fabricated within the soft material of each fingertip to enable real-time contact and pressure sensing. The monolithic fabrication eliminates assembly requirements and ensures robust interfacial bonding. Experimental results demonstrate the gripper’s ability to securely grasp a variety of objects with different weights (up to 0.5kg), sizes and fragilities. The integrated sensors successfully detected contact events and provided a proportional response to applied pressure, validating the proposed design and manufacturing approach for creating complex, multi-functional soft robotic systems. soft robotic gripper fabricated in a single print cycle. The monolithic design integrates sensing and structure, resulting in a 28% higher payload-to-weight ratio and a 37% improvement in durability over conventional assembled grippers.

Keywords:Soft robotics; Additive manufacturing; PolyJet; Monolithic fabrication; Sensor integration