Effects of Bending Curvature and Structure of Coil-Shaped Carbon Nanotube Composite for Thickness Measurement

This article investigates the properties of intrinsically flexible composite materials as sensing elements for thickness measurement. The advantages and effects, such as flexibility and structure, are studied. The characterization of coil-shaped carbon nanotube composites is described, which exhibits good sensitivity and adaptability in various measurement scenarios. The study systematically investigates the effects of sensor structure (e.g., size, turns), curvature, and excitation source edge effect on the accuracy and reliability of thickness measurements. Experimental results show that the coil-shaped carbon nanotube composite proposed in this article exhibits good and consistent response characteristics during thickness measurement. This response trend remains invariant regardless of variations in the sensor’s own structure or bending degree. However, factors, such as structure and bending curvature, cause deviations in the induced electromotive force (emf) output during thickness measurement, which demonstrate regularity under controlled experimental conditions. Moreover, deviations occurring in the excitation coil during the measurement process directly influence the output characteristics of the sensing element for thickness measurement, potentially rendering the measurement impossible in the end. Through a series of experiments and theoretical analyses, the sensing elements’ behavior under different conditions is demonstrated and a reference for the characteristics of coil-shaped carbon nanotube composite thickness sensing elements for thickness measurements in different practical application environments that may exist.