TiBCLaG: A Trigger-induced Bistable Compliant Laparoscopic Grasper

2026-03-19

AI Summary

This study addresses the high manufacturing and assembly costs of conventional laparoscopic graspers, which rely on multi-link rigid mechanisms. The authors propose a monolithic, fully compliant bistable grasper that, for the first time, integrates a bistable compliant mechanism into laparoscopic instrumentation. By coupling a compliant trigger with the end effector, the design achieves stable grasping without requiring continuous actuation. The trigger mechanism is synthesized using a dual-beam constraint model, and a functional prototype is fabricated through nonlinear finite element analysis and fused deposition modeling 3D printing. Experimental results demonstrate reliable bistable actuation and adaptive grasping capability, effectively mitigating buckling-induced instability. This work establishes a new paradigm for low-cost, high-performance compliant surgical instruments.

Technology Category

• Intelligent Robots: Manipulation
• Multiagent Systems: Mechanism Design
• Constraint Satisfaction and Optimization: Constraint Learning and Acquisition

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments

Abstract

Industrial laparoscopic graspers use multi-link rigid mechanisms manufactured to tight tolerances, resulting in high manufacturing and assembly costs. This work presents the design and proof-of-concept validation of a monolithic, fully compliant, bistable, laparoscopic grasper that eliminates the need for multiple rigid links, thereby reducing part count. The device integrates a compliant trigger and a compliant gripper end-effector, coupled via a control push-rod, to achieve stable grasping without continuous user input. The trigger mechanism is synthesized using a Two-Element Beam Constraint Model as a design framework to control the deformation and stiffness of V-beam-like elements. This technique enables elastic energy storage while preventing snap-through instability. The end-effector is designed as a compliant gripper to achieve adaptive grasping through elastic deformation. Jaws' opening-and-closing performance is demonstrated using nonlinear finite element analysis. The laparoscopic design presented here is fabricated using fused deposition 3D printing. The fabricated prototype demonstrates reliable bistable actuation, confirming the feasibility of such compliant laparoscopic grasper architectures.

Problem

• laparoscopic grasper
• compliant mechanism
• bistable
• manufacturing cost
• rigid links

Innovation

• compliant mechanism
• bistable actuation
• laparoscopic grasper
• beam constraint model
• 3D printing