The design of sweeper frequency and resonant frequency tracer based on DDS AD9850 for application on microcantilever sensor

Abstract

A frequency sweeper and resonant frequency tracer have been developed to detect the resonant frequency on the microcantilever sensor. Frequency sweepers and frequency trackers are very important to develop microcantilever sensors, especially measurements of sensitivity, response time, and reproducibility. This developed system uses Arduino as a microcontroller to control AD9850 direct digital synthesizer (DDS) to produce sinusoidal voltage signal with an amplitude of ± 0.5 volts at a certain frequency. This signal was amplified up to ± 10 volts, then transmitted to the piezoelectric in order to vibrate the microcantilever sensor in a certain frequency. The microcantilever resonant frequency can be determined by frequency sweeper when the signal reaches its maximum amplitude. Frequency tracer was developed to record changes in the resonant frequency of the microcantilever due to objects mounted on the surface of the microcantilever. The frequency measurement results are validated by comparing its outputs to the other devices which was developed by Shizuoka University. The final results that the microcantilever has a natural frequency of 36.41kHz.