Bifurcation analysis and complex phenomena in self-excited microcantilevers

Sensors based on self-excitation of microcantilevers have been proposed as effective devices for the measurement of rheological properties of the fluid where they are immersed. However, embedding microcantilevers in a feedback loop causes complex phenomena that need to be investigated. Specifically, a variable delay in the loop originates jumps in the oscillation frequency. In this paper, we study the nonlinear dynamics of a self-excited microcantilever oscillating in viscous fluids. Using DDE-Biftool, a Matlab package for numerical bifurcation analysis of DDEs, we investigate the bifurcations of periodic solutions in one and two parameters. The numerical results are compared with some experimental data of previous studies. •The delay is a key factor to affect the stability and frequency jumps.•Bifurcations critical conditions mainly depend on the quality factor.•The model foresees jumps and the associated hysteresis region observed experimentally.