Microorganisms' undulatory swimming in anisotropic fluids near a flat wall has emerged as a key area of interest, driven by the potential to inform the design and fabrication of microdevices through a deeper understanding of their complex behaviors. However, the swimming mechanism has not yet been clarified. To address this gap, we employ asymptotic analysis and numerical study to investigate the dynamics of microswimmers swimming near a wall in lyotropic liquidcrystal polymers at low Reynolds numbers using Doi's Q-tensor model. Our study reveals that infinitely long sheets (i.e., Taylor's swimming sheet model) speed up as they are next to the wall, accompanied by a notable increase in swimming efficiency, surpassing those observed during the free swimming scenario. We demonstrate that stiff finite-length swimmers can gradually reorient themselves and be trapped when close enough to the wall, due to a net hydrodynamic torque induced by the asymmetric distribution of the flow field around the body. These findings suggest that the wall effect is pivotal in microorganisms' swimming performance.

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• Low Reynolds number swimmers
• Microswimmers
• Complex fluids
• Non-Newtonian fluids
• Immersed boundary methods