A novel carbon nanotubes (CNTs) film displacement sensor for countersink depth control

Abstract

A novel displacement sensor based on glass fiber reinforced composite (GFRP) and carbon nanotubes (CNTs) film was developed using the sensitivity of the three-dimensional network structure of CNTs films to bending stress and strain changes. The sensor was applied to the control of the countersink depth with a relatively ideal verification result. The three-point bending experiment was used to explore the influence of three types of displacement sensors with different thicknesses and embedded positions between the CNTs film layers on their resistance signals and combined with the microscopic mechanism for analysis then carry out the repeatability, response time, and countersink depth test of the sensor. The experimental results show that the displacement sensor can fully withstand the deformation with a bending deflection of 10 mm. Its resistance change ratio and displacement have a high degree of goodness of fit quadratic relationship with R2 up to 0.99. Compared with the embedded position of the CNTs film, the thickness of the sensor is extremely sensitive to the sensing performance. The sensor has good repeatability, rapid response, recovery capability, and can control the accuracy of the countersink depth within ±0.05 mm with an accuracy rate of 91 %.