A method of fabricating a microlens array, the method comprising the steps of: compressing a shape memory polymer substrate with a predetermined load; indenting the shape memory polymer substrate to form an array of micro-indents; immersing the shape memory polymer substrate in a solvent capable of causing stress-enhanced swelling in the shape memory polymer substrate such that the array of micro-indents forms a corresponding array of micro-protrusions on the shape memory polymer substrate due to the stress-enhanced swelling of the micro-indents; and heating the shape memory polymer substrate to form at least one curved surface of the shape memory polymer substrate under the micro-protrusion array.