Utilization of carbon nanofibers for airborne ultrasonic acoustic field detection using heterodyne interferometry

Carbon nanofibers and nanotubes are currently being utilized as active elements in acoustic sensors for emerging microelectromechanical systems and nanoelectromechanical systems technologies. A methodology for measuring the displacement of carbon nanofibers in combination with heterodyne interferometry is reported here. Experimental results show that ultrasonic field detection is possible using this technique, and results are presented for measurements in the ultrasonic frequency range. This approach could potentially lead to new calibration methods for ultrasonic sensors. A different approach to that of interferometry is also reported for future investigation.