Nonlinear dynamics in MEMS systems: Overcoming pull-in challenges and exploring innovative solutions

Abstract

Micro-Electro-Mechanical Systems (MEMS) play a pivotal role in modern technology, with applications ranging from biomedical monitoring to inertial navigation, RF communication, and energy harvesting. However, their nonlinear dynamics, arising from electrostatic coupling, geometric and material nonlinearities, and multi-physics interactions, present substantial challenges. Pull-in instability, predominantly initiated by even-order nonlinear terms, signifies a pivotal concern that can culminate in device failure, stiction, and irreversible damage. This paper presents novel methodologies for the comprehensive elimination of pull-in instability in MEMS. The re-engineering of the spring in the MEMS oscillator has yielded a specialized spring with a meticulously designed restoring-force formula, which effectively counteracts the influence of even-order nonlinear forces to mitigate pull-in instability. Furthermore, modifying the MEMS system’s structure, material properties, or governing equations to eliminate the quadratic nonlinear term—a primary cause of pull-in instability—significantly delays the onset of pull-in, despite the persistence of higher-order even nonlinearities. A novel MEMS model has been developed to address higher-order even nonlinearities with high effectiveness. When parameters Ω i and ω i are suitably chosen, this model fully eliminates all even nonlinearities. Furthermore, AI-assisted modeling techniques are employed to capture the complex nonlinear behaviors of MEMS with high accuracy and efficiency, enhancing device design and enabling effective control strategies. The integration of these approaches offers a comprehensive solution to the problem of pull-in instability, thereby creating new possibilities for the development of more reliable, efficient, and innovative MEMS devices. These developments will have profound impacts across multiple application fields.