An evaluation technique for high-frequency dynamic behavior of a sandwich microcantilever beam

A method was developed to measure the first- and second-order vibration modes in a sandwich microcantilever beam oscillating in the megahertz frequency regime in the present study. Taking advantage of the ultrasonic frequency, a test platform was developed to induce free vibration of the microcantilever using a high-power radio frequency pulser that transmits tone burst signals to a contact transducer, and the resonant frequencies of the microcantilever were measured using a laser-optic interferometer. Results show that the microcantilever’s vibration above 8 MHz can be successfully detected, and its vibration modes were identified through a theoretical study based on the Euler–Bernoulli beam theory and a numerical analysis using the finite element method. The present study proposes a facile and effective way to actuate a high-speed sandwich microcantilever and detect its high-frequency response so that the technique can be employed to study the characteristics of micro- and nanomechanical sandwich structures and their properties.