Embedded electro-conductive yarn for shape sensing of soft robotic manipulators

Area of Science:

• Robotics
• Medical Devices
• Materials Science

Background:

• Flexible soft robotic manipulators offer improved maneuverability in Minimally Invasive Surgery (MIS) compared to rigid instruments.
• Precise position feedback control for soft robots is crucial but challenging, necessitating effective shape sensing.
• Previous work integrated optical fibers for pose estimation in soft manipulators.

Purpose of the Study:

• To present an enhanced, miniaturized embedded bending/shape sensor for soft robotic manipulators.
• To develop a sensor capable of measuring both bending behavior and elongation.
• To integrate and evaluate the sensor's performance in a pneumatically actuated soft manipulator.

Main Methods:

• Developed a novel shape sensor using electro-conductive yarn helically wrapped around an elastic strap.
• Protected the yarn sensor within a 1.5mm outer-diameter stretchable pipe.
• Integrated three stretch sensors into the periphery of a soft manipulator to measure actuation chamber lengths.

Main Results:

• The enhanced sensor system is miniaturized and capable of measuring bending curvature and elongation.
• Direct measurement of actuation chamber lengths was achieved through integrated stretch sensors.
• The system's capability in evaluating bending and elongation of the soft manipulator arm was demonstrated.

Conclusions:

• The electro-conductive yarn-based sensor offers a viable solution for shape sensing in soft robotic manipulators.
• This technology enhances precise position feedback control for soft robots in MIS.
• The miniaturized and versatile sensor contributes to the advancement of flexible surgical tools.