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Updated: Feb 25, 2026

Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery
Published on: November 14, 2015
Development of a novel robotic platform with controllable stiffness manipulation arms for laparoendoscopic
Jianchen Wang1, Shuxin Wang1, Jinhua Li1
1Key Lab for Mechanism Theory and Equipment Design of Ministry of Education, School of Mechanical Engineering, Tianjin University, Tianjin, China.
Background:
For current LESS robotic systems, the trade-off between dexterity and payload capability is always present. This paper presents a novel LESS robotic platform equipped with controllable stiffness manipulation arms.
Methods:
Each manipulation arm with an articulated section and a controllable stiffness continuum section (CSCS) can be switched between a 7-DoF compliant status and 5-DoF rigid status according to the operation requirement. Screw theory and product exponential formula are used to quantify the kinematic performance.
Results:
The stiffness of the manipulation arm promotes 3.03 to 4.12 times from compliant to rigid CSCS with maximum payload of 10 N in rigid status. The shortest rigid/compliant switching time is 5 s. The precision of a tracking test and an ex vivo procedure verified the accuracy and effectiveness of the controllable stiffness manipulation arms.
Conclusions:
This robot could potentially improve the surgical performance and further expand robotic LESS procedures.

