Poly(2-oxazoline)s (POx) bottle-brush brushes have excellent biocompatible and lubricious properties, which are promising for the functionalization of surfaces for biomedical devices. Herein, a facile synthesis of POx is reported which is based bottle-brush brushes (BBBs) on solid substrates. Initially, backbone brushes of poly(2-isopropenyl-2-oxazoline) (PIPOx) were fabricated via surface initiated Cu-0 plate-mediated controlled radical polymerization (SI-(CuCRP)-C-0). Poly(2-methyl-2-oxazoline) (PMeOx) side chains were subsequently grafted from the PIPOx backbone via living cationic ring opening polymerization (LCROP), which result in approximate to 100 % increase in brush thickness (from 58 to 110 nm). The resultant BBBs shows tunable thickness up to 300 nm and high grafting density (sigma) with 0.42 chains nm(-2). The synthetic procedure of POx BBBs can be further simplified by using SI-(CuCRP)-C-0 with POx molecular brush as macromonomer (M-n=536 g mol(-1), PDI=1.10), which results in BBBs surface up to 60 nm with well-defined molecular structure. Both procedures are significantly superior to the state-of-art approaches for the synthesis of POx BBBs, which are promising to design bio-functional surfaces.