A Flexible Conformal Piezoresistive Sensor Based on Electrospinning for Deformation Monitoring of Carbon Fiber-Reinforced Polymer

Carbon fiber-reinforced polymer (CFRP) materials are widely applied in various areas as key structure components. The structural health monitoring of the CFRP components is crucial to prevent catastrophic failure. However, the nonplane surfaces of CFRP components hinder the attaching of monitoring sensors with hard substrates. Therefore, the substrate conditions for sensor preparation are mainly considered in this study. To adapt the proposed sensors to the curved substrate, including nondevelopable surfaces, electrospinning method is used to prepare conformal piezoresistive fiber films, in which polymethyl methacrylate is served as the matrix and carbon nanotubes are utilized as the conductive filler. The piezoresistive fibers covered on CFRP substrates have a gauge factor up to 207.95 and can response to the strain less than 0.05%. Moreover, the sensor also has high durability and the ability to follow the dynamic excitation signals with as high as 50 Hz.