In a first aspect, an apparatus for cleaning a thin disk is provided. The apparatus includes a support roller for supporting a rotating wafer within a wafer cleaner. The support roller comprises a guide portion, for receiving an edge of a wafer, having an inclined surface comprising a low-friction material and adapted to allow the wafer edge to slide thereagainst; and an edge-trap portion for retaining the edge of the wafer and having a transverse surface comprising a high-friction material and adapted, when in communication with the edge of the wafer, to resist sliding thereagainst. Numerous other aspects are provided.