Bioconvective analysis of micropolar nanofluid with gyrotactic microorganisms over a spinning needle used in biosensing and targeted drug delivery

: The bioconvective flow in nanofluid presents significant attention in biomedical as well as microfluidic technologies due to its potential in enhancing biosensing and targeted drug delivery accuracy. The present analysis is intended for the bioconvection of a two-phase modelled micropolar nanofluid consisting of microorganisms over a spinning needle, where the integration of Brownian motion and thermophoresis plays an important role in the flow phenomena. Additionally, the role of the Hall current and the influence of Joule and Darcy dissipation on the flow of a conducting fluid within a permeable medium significantly affect the flow behavior. The insertion of gyrotactic microorganisms induces bioconvective motion, which enhances the uniformity of the particles and prevents agglomeration. The governing mathematical model, presenting the flow patterns, is transmuted into the standard dimensionless model by exploiting similarity conditions, and further, shooting, accompanied by the Runge-Kutta numerical technique, is used in handling the model. The comparative analysis with the earlier investigation is obtained numerically, which validates the current methodology in particular cases. The results reveal that Hall and magnetic field interactions significantly influence the azimuthal velocity, while Joule and Darcy dissipation increase the thermal boundary layer thickness.