Rapid investigation of nanocrystalline diamond vibrating membranes with a stroboscopic interferometer

Nanocrystalline diamond is a promising material for the fabrication of highly sensitive flexural plate wave (FPW) sensors. The design of the FPW sensor requires the determination of the mechanical properties of a thin film membrane. In this paper we investigate the mechanical resonance of nanocrystalline diamond membranes with a stroboscopic interferometer optical system. Membranes with lateral dimensions in the range 0.8 to 6 mm and about 1 /spl mu/m thick were excited in air by a loudspeaker. The resonance frequencies helped to determine the mechanical properties of the diamond membrane and give directly the parameter of interest for the FPW sensor design. Our method allows the rapid investigation of the material without requiring an integrated transduction system and can be used to analyze structures with the actual dimensions of the FPW sensor.