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Prof. Yong Shi and his PhD student Shiyou Xu from Stevens have been selected to receive the 2007 American Society for Nondestructive Testing (ASNT) Fellowship Award for their research on 'Fabrication and Characterization of Nano AFC's as Acoustic Emission Sensors'  during the 2007 ASNT Fall Conference and Quality Testing Show in Las Vegas, Nevada, November 12-16, 2007.

Active Fiber Composites (AFC) present a number of advantages in comparison with conventional acoustic emission (AE) sensors, such as lightweight, flexibility (adaptable to curved surfaces), anisotropic sensitivity, and potential for integration into composites for real time structure health monitoring.  However, the thickness of the typical AFCs is about 300 µm due to the large fiber diameter (125 µm or more). Although the manufacturing processes are compatible with polymer matrix laminates, their diameters are too large to be embedded in, for example, graphite fiber composites which have fiber diameters of a few microns. Piezoelectric nanofibers developed at Prof. Shi's lab in Mechanical Engineering Department can potentially solve this problem when used in the form of Nano AFCs. The nanofibers developed by electrospinning processing could be readily used as reinforcements, sensors and also actuators for nano AFCs. New process are currently being developed to integrate piezoelectric nanofibers with matrix materials and electrodes using micro fabrication methods.  Due to their nanoscale size, the Nano AFC sensors could couple much higher sensitivities with much low driving voltage as compared to traditional sensors. Additional information can be found here.