Carbon nanotube/glycerol embedded low cost flexible sensor for large deflection sensing of continuum manipulators

摘要

Abstract Large deflection sensing is highly crucial for proper positioning and control of continuum robots during robot assisted minimally invasive surgery (MIS). Existing techniques suffer from eletromagnetic noise susceptibility, harmful radiation exposure, limited range, bio-incompatibility and necessity of expensive instruments. In the present study, we propose a multi-walled carbon nanotubes/polyglycerol based low cost, flexible and biocompatible sensor which could allow safer, faster and accurate angular deflection measurement of continuum robots for biomedical applications. Experimental results demonstrate that the sensor is stretchable up to 100%, provides a gauge factor up to 11.65, have response time around 8 ms, durability of −0.14% for cyclic loading and unloading and show very small creep up to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>±</mml:mo> <mml:mn>0.0008</mml:mn> <mml:mtext> </mml:mtext> <mml:mo stretchy="false">(</mml:mo> <mml:mo>±</mml:mo> <mml:mn>2.88</mml:mn> <mml:mi mathvariant="normal">%</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:math> . Furthermore, the sensor can measure continuum robot deflection up to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>±</mml:mo> <mml:msup> <mml:mn>150</mml:mn> <mml:mrow> <mml:mo>∘</mml:mo> </mml:mrow> </mml:msup> </mml:math> with a sensitivity of 666.67 ohms/degree, with a maximum error of 1.67% and maximum hysteresis of 1.41%. Thus, wide range, low cost, fast response, and biocompatibility justify the potential of the proposed sensor for large deflection sensing of continuum robots during robot assisted MIS.