Multistability phenomenon in signal processing, energy harvesting, composite structures, and metamaterials: A review

Multistability is the phenomenon of multiple coexistent stable states, which are highly sensitive to perturbations, initial conditions, system parameters, etc. Multistability has been widely found in various scientific areas including biology, physics, chemistry, climatology, sociology, and ecology. In a number of systems where multistability naturally exists, it is found to be undesirable because of the involuntary interwell or chaotic switching among dynamical states that disorder the systems and cause instability. However, in recent decades, researchers have identified numerous benefits of multistability and have devoted research efforts to artificially creating it for a wide range of applications, including signal processing, energy harvesting, composite structures and metamaterials, and micro-/nano-electromechanical actuators. This is because of the unique characteristics of multistability, such as rich potential structure, interwell dynamics, broadband nature, and alleviation of the input energy to sustain stable states, which may play different advantageous roles depending on their applications. In this review, we introduce how researchers create the key of multistability and utilize it to open a new world of theories, materials, and structures. We concentrate on developing histories from bistability to multistability in several potential applications. Different designs of digital and physical multistable systems, and their modeling, performance quantifiers, advantageous mechanisms, and improved techniques are reviewed and discussed in depth. Furthermore, we summarize the key issues and challenges of application-oriented multistability and the corresponding possible solutions, from the phenomenon itself to its realistic implementation. Finally, we provide the prospects for future studies on multistability in more developing research fields.