Development of Carbon Nanotube/Polyvinyldene Difluoride Nanocomposite based Force Sensor System

摘要

Multi-walled carbon nanotube reinforced polyvinyldene difluoride (PVDF) nanocomposites were used to develop a force sensor system to measure and monitor cutting forces. The nanocomposites were fabricated using a compression molding technique and electrically polarized to convert the PVDF into a piezoelectric beta phase. Electrical characterization of the nanocomposites was performed using an electrochemical impedance spectroscopy technique, and an electrical model was generated that incorporates both the piezoresistive and piezoelectric characteristics of the nanocomposite. The force sensing capabilities of both poled and non-poled nanocomposite specimens were examined by applying known forces. The poled specimens showed higher force sensitivity, due to the contribution of both the piezoresistive and piezoelectric characteristics of the nanocomposite. To improve the sensitivity and robustness of the force sensing, 12 poled nanocomposite specimens were used to construct a force sensor system. To validate the effectiveness of the force sensor, orthogonal cutting tests were performed. The cutting forces measured by the nanocomposite force sensor system showed comparable results to a commercially available table dynamometer.