SPICE-Based Multiphysics Model to Analyze the Dynamics of Ferroelectric Negative-Capacitance–Electrostatic MEMS Hybrid Actuators

Abstract

We propose a framework to model ferroelectric negative capacitance: electrostatic Micro Electro Mechanical Systems (MEMS) hybrid actuators and analyze their dynamic (step input) response. Using this framework, we report the first proposal for reduction in the dynamic pull-in and pull-out voltages of the hybrid actuators due to the negative capacitance of the ferroelectric. The proposed model also reveals the effect of ferroelectric thickness on the dynamic pull-in and pull-out voltages and the effect of ferroelectric damping on the energy dissipated during actuation. We infer from our analysis that the hybrid actuators are better than the standalone MEMS actuators in terms of operating voltage and energy dissipation. Further, we show that one can trade-off a small part of the reduction in actuation voltage to achieve identical pull-in times in the hybrid and standalone MEMS actuators, while still consuming substantially lower energy in the former as compared to the latter. The circuit compatibility of the proposed hybrid actuator model makes it suitable for analysis and evaluation of various heterogeneous systems consisting of hybrid MEMS actuators and other electronic devices.