Nanocomposite functional bond with carbon nanotubes

In this paper we show the importance of the interface integrity for a piezoelectric (PZT) actuator/sensor, surface bonded to a metal substrate and we investigate the use of carbon nanotubes (CNTs) in order to improve the interface performance. This study shows that the interface is critical, the loss of its integrity can in fact have a detrimental effect on the performance of the PZT actuators. The key feature of the proposed design is to integrate carbon nanotubes into the adhesive layer between the structure and the actuators. The effect of CNTs orientation and dispersion on the interface shear strength was also studied. It is shown that the integration of a high-density array of oriented CNTs into the adhesive bond has the potential to improve significantly the interface shear strength up to 274%, however a wide data dispersion is also observed and probably addressable to the ratio between the length of the CNTs and the actual interface thickness. When randomly oriented CNTs are embedded into the adhesive layer, the shear strength doesn't show a meaningful variation if compared to the standard adhesive case. The orientation of a high density array of CNTs and their dispersion into the adhesive layer was achieved by means of a low-cost and low-temperature fabrication process.