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Abstract

This research introduces a hybrid robotic gripper designed to achieve compliant; strong; and reliable grasping for automation tasks involving fragile or geometrically diverse objects. Rigid grippers offer high load capacity; however, they often damage delicate items during manipulation; soft grippers provide safe contact; yet lack the force required for firm grasping. This trade-off limits overall functionality in uncontrolled environments where object types and shapes vary frequently. A major design challenge continues to involve achieving adaptive grasping of irregular geometries through passive mechanical strategies without depending on complex sensors or advanced feedback algorithms. The main objective of this research was to design, simulate; and experimentally evaluate a new gripper structure that permits passive shape adaptation during safe and effective handling of various objects. The process employed software-based kinematic modeling to define motion characteristics and reachable workspace; followed by fabrication and validation of a prototype constructed using lightweight aluminum components and corrugated TPE-PE pneumatic bellows. A key innovation was the “Four L-Shaped Links” kinematic layout that translated basic pneumatic inflation into an organized multi-point wrapping motion; mechanical compliance was achieved through design features rather than software. The final prototype achieved a maximum grasp span of 98 mm with a full actuation duration of 3.2 seconds at 120 kPa. Physical tests confirmed reliable manipulation across multiple object types; with a peak lifting capacity of 980 g; including secure grasping of both rigid and soft items without inflicting surface damage. The outcome is a reliable, manufacturable, and task-effective gripper bridging limitations of rigid and soft technologies, suitable for agriculture, logistics, and assistive use cases demanding precision and strength.