Why Doesn't The Lotus Leaf Get Wet?

This is because of the outlayers of cells in the epidermal layer of the leaves. They have a material called cellulose which, due to a process known as cutinization get converted into cutin and this layer of cutin forms an impermeable membrane called cuticle on the walls of the cells.

Cuticle is a wax like substance and is highly insoluble in water and is also chemically inert. This wax-like material forms a protective covering. This formation is more pronounced in the lotus leaf and that is why the lotus leaf doesn't get wet.