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arXiv · 2607.17840

A Compact 3D-Printed Soft Finger with Cyclic Hydraulic Actuation

Zefang Mao·Yunjia Li·Victoria Bamgboye·Sara Ben Haj Hammouda·Aika Ono·Wen Fan·Chao Wu·Dandan Zhang
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Abstract

Hydraulic soft fingers offer compliant and gentle manipulation, but their practical deployment is limited by bulky fluidic hardware, fabrication complexity, and insufficient design validation. This paper presents a compact 3D-printed soft hydraulic finger driven by a miniature cyclic peristaltic loop. The finger integrates compliant bellows, rigid connectors, and fluidic ports, while an Abaqus fluid-structure model is used to guide selection of wall thickness, pitch angle, and bellows length. The selected design is validated through baseline-corrected chamber-pressure measurements and vision-based angle tracking. Results show that the quasi-static finite-element model captures the main pressure-angle trends, with remaining offsets mainly attributed to bonding-induced stiffness and hydraulic losses. Vision-feedback control further enables repeatable angle tracking over a large bending range. Finally, grasping tests on fragile and deformable objects, including tofu and blueberries, demonstrate gentle, slip-free contact without visible damage. Overall, this work establishes a reproducible pipeline from FEA-guided design to closed-loop validation for compact 3D-printed hydraulic soft fingers.

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Zefang Mao, Yunjia Li, Victoria Bamgboye, Sara Ben Haj Hammouda, Aika Ono, Wen Fan, Chao Wu, Dandan Zhang. 2026-07-20. A Compact 3D-Printed Soft Finger with Cyclic Hydraulic Actuation. https://arxiv.org/abs/2607.17840

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