Nonlinear dynamics of micro-scale floating mass transducer oscillator under electrical and mechanical excitation

In the paper, a small-sized system with a Floating Mass Transducer (FMT) was investigated. Such a device can be used for vibration excitation (FMT as a vibration actuator) or for energy recovery (FMT as an energy harvester). Both applications were tested during the research. The developed FMT model accounts for the existence of two induction coils, whose connection configuration affects the electromechanical coupling in the system. The main goal of the paper is to show that for large oscillations, the two selected FMT configurations exhibit significantly different dynamic behaviors, while CMFT and DMFT exhibit identical responses in the linear regime. Their behaviors diverge markedly under strong excitations: the CFMT undergoes an earlier transition to multi-harmonic and chaotic responses, whereas the DFMT maintains quasi-linear characteristics over a broader operating range. Moreover, the study distinguishes between the dynamical effects of electrical and mechanical excitation sources, showing that electrical actuation induces complex subharmonic and chaotic phenomena, while mechanical excitation leads predominantly to superharmonic responses. To capture these behaviors, a dedicated FFT-based characterization framework was developed, overcoming the limitations of conventional analytical tools in describing strong nonlinearities. Finally, by contrasting actuator and energy-harvesting regimes, this work uncovers subharmonic generation as a key mechanism differentiating their dynamics, providing new insights for FMT devices operating in nonlinear domains. The study is intended as a theoretical and signal-oriented investigation of nonlinear response mechanisms, rather than a device validation or performance optimization study.