The main goal of this work is to investigate how the initial stress affects a thermoelastic micro-elongated layer under a layer of piezoelectric loading using the theory of Lord-Shulman (L-S) with relaxation time and the model of dual-phase-lag (DPL) with two relaxation times. The normal mode analysis is used to transform the partial differential equations into ordinary differential equations. The numerical computations are carried out and the outcomes are visually presented. It is shown that initial stress has a significant impact on all physical quantities, as demonstrated by a comparison of the DPL mod and the L-S theory in both full absence and presence of initial stress.