a method of depositing or etching a micro - or nano - scale pattern on a work piece is disclosed , including the steps of : placing the work piece in an electrochemical reactor in close proximity to a patterned tool ; connecting the work piece such that it is the anode if is to be etched or the cathode if it is to be deposited , and the patterned tool such that it is the counter electrode ; pumping electrolytic fluid necessary for the electrolytic operation of the cell formed between the two electrodes ; and applying a current across the electrodes to etch or deposit the work piece .