Abstract <p>This article presents the propagation of waves in a functionally graded micropolar thermoelastic plate in the presence of diffusion and memory-dependent derivatives (MDD). The material properties are assumed to be functionally graded and non-homogeneity vary exponentially along the -direction. The basic equations are converted into dimensionless form and Helmholtz decomposition technique is employed to simplify these equations. The analytical expressions for potential functions, temperature, mass concentration and micro-rotation are obtained by using normal mode analysis. Normal mode analysis method is momentous as it relinquishes complex coupled dynamics into easier explicable and analyzable components disclosing wherein system inherently react, convulse or rebound to stimulants. The propagation equations for insulated impermeable and iso-thermal iso-concentrated boundaries are obtained. The magnitudes of force stresses, couple stresses, mass concentration and temperature for the symmetric and asymmetric systems are calculated using the suitable boundary conditions. The analytically obtained results are numerically analyzed for aluminium-epoxy material under Lord-Shulman (LS) and Green-Lindsay (GL) models for different kernel functions and non-homogeneity parameters. This study is useful for researchers working in thermodynamic engineering, material science and micropolar thermoelastic diffusion model under different physical parameters.</p>