It is shown that a three-dimensional plasma sheath lens that forms on biased electrodes interfacing insulators exhibits novel characteristics such as ion focusing on desired locations, controllability of ion flux uniformity, formation of passive surfaces and applicability to plasma diagnostics. The ion flux profile on substrates of different geometry is obtained by three dimensional simulations of potential distribution and ion trajectory, while experiments are realized in electropositive and electronegative DC and ICP discharges. (c) 2006 Elsevier B.V All rights reserved.