<p>This study investigates the electroosmotic flow (EOF) of a Newtonian fluid in a microchannel formed by two parallel plates, focusing on enhancing accuracy and extending the applicability to a broader range of zeta potentials. The analysis employs the Akbari Ganji method (AGM) to solve the governing equations, including a modified Navier–Stokes equation and the Poisson–Boltzmann equation, without relying on the traditional Debye–Hückel approximation. This method makes it possible to anticipate the electroosmotic flow behavior with more accuracy, especially in situations with high zeta potentials, which are frequently found in real-world medical applications. The energy equation for evaluating the temperature distribution is refined using a scale analysis, and the Nusselt number is computed using the determined temperature profile. Our numerical predictions demonstrate strong agreement across a wide range of zeta potentials, revealing the dependency of the Nusselt number on the electrokinetic length. The findings highlight the effectiveness of the proposed model in predicting EOF in microchannels, providing a robust framework for future research in electrokinetic transport applications, particularly in medicine and drug delivery, where precise control of fluid flow is crucial.</p>