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Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery
Published on: November 14, 2015
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Flexible Manipulator with Low-Melting-Point Alloy Actuation and Variable Stiffness
Haibo Wang1, Zhiwei Chen1, Siyang Zuo1
1Key Lab of Mechanism Theory and Equipment Design, Ministry of Education, Tianjin University, Tianjin, China.
Soft Robotics
|June 21, 2021
Summary
This study introduces a novel flexible manipulator for minimally invasive surgery that uses a low-melting-point alloy to achieve adjustable stiffness. The manipulator demonstrates rapid, controllable transitions between rigid and flexible states, enhancing surgical capabilities.
Area of Science:
- Robotics
- Biomedical Engineering
- Materials Science
Background:
- Flexible manipulators offer advantages in minimally invasive surgery due to their ability to navigate complex anatomical pathways.
- A key limitation of current flexible manipulators is their insufficient stiffness, hindering precise control and force application.
Purpose of the Study:
- To develop and evaluate a novel flexible manipulator with actively controllable stiffness for surgical applications.
- To investigate the use of low-melting-point alloy phase transformation for hydraulic actuation and stiffness modulation.
Main Methods:
- Fabrication of a prototype flexible manipulator utilizing a low-melting-point alloy.
- Experimental evaluation of motion control, stiffness performance, and transition efficiency between rigid and flexible states.
- Characterization of lateral and flexural stiffness in both states and assessment of ultimate force without deformation.
Main Results:
- The manipulator demonstrated free adjustment of heading direction in 3D space.
- Transition times were 9.2–10.3 s (rigid to flexible) and 15.4 s (flexible to rigid).
- Significant stiffness gains were achieved: lateral stiffness increased by 13.15x and flexural stiffness by 477.05x, with substantial load-bearing capacity in the rigid state.
Conclusions:
- The proposed manipulator successfully achieves controllable stiffness modulation via phase transformation of a low-melting-point alloy.
- The demonstrated performance highlights its potential for enhancing diagnostic and therapeutic functions in minimally invasive surgery.
- This technology offers a promising solution for overcoming the stiffness limitations of flexible surgical instruments.
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