<p>With the rapid development in additive manufacturing technologies, the demand for metamaterials characterized by adjustable mechanical features for interdisciplinary engineering applications has become increasingly popular, particularly in sophisticated small-scale systems. This paper pays attention to exploring the dynamic instability responses of functionally graded microplates fabricated from nature-inspired triply periodic minimal surface (TPMS) lattice architectures. The size-dependent instability dynamic behavior of three different sheet-based TPMS lattice architectures: Primitive, Gyroid, and I-graph and Wrapped Package-graph, is analyzed using modified couple stress theory. This study examines TPMS cellular architectures within the framework of uniform and two gradient density distributions. In addition, graphene is uniformly distributed within the TPMS structures to improve the dynamic performance. The dynamic instability regions in this investigation are determined using Bolotin’s procedure. The present findings reveal that the dynamic performance of TPMS lattice architectures outperforms that of both open-cell and closed-cell cellular solids. Additionally, the distribution and density of porosity in TPMS architectures significantly influence structural stiffness. A symmetric porosity pattern is found to yield the best dynamic instability performance, while structural rigidity is significantly enhanced by the addition of graphene. Furthermore, increasing the material length scale ratio and graphene weight fraction results in improved size-dependent dynamic instability characteristics. The present findings bring valuable insights into dynamic performance as well as contribute to the development of advanced lattice structures at the small scale, inspired by nature and reinforced with graphene.</p>