This anti-backlash gear includes a gear wheel and gear teeth. Each gear tooth comprises first and second flanks, a top face and a bottom face, wherein for each gear tooth each flank extends from the top face to the bottom face, wherein the gear teeth comprise a polymeric material which comprises a repeat unit of form I wherein t1, and w1 independently represent 0 or 1 and v1 represents 0, 1 or 2. For each gear tooth, at least one of said flanks comprises two or more surfaces arranged to form a single protrusion extending along the at least one said flank such that a tooth thickness of each gear tooth varies between the top face and the bottom face of said gear tooth in a direction parallel to an axis of rotation of the gearwheel in operation. In use, the single protrusion is elastically deformable so as to absorb backlash.