Miniaturized motors or circuits are usually manufactured by the electrodeposition of copper on micropatterned substrates, with feature dimensions of the order of 50 mu m. Local growth rate over such electrodes can be predicted by numerical codes of increasing capacity and accuracy, but very few experimental data are available for validation of these codes, due to the technical difficulty in measuring local current density over the microfeatures. The paper deals with the development and the use of a similarity approach for the design of an enlarged scale model to enable local variables to be measured at the active area of the features. The dimensions of the scale model have to allow microelectrodes or other microsensors to be inserted in the active horizontal and vertical walls of the features, and the operating conditions have to be representative to those in the actual, microscale system, with respect to mass, momentum, and charge transfers. The case of laminar flow over patterned electrodes with inactive area at the bottom of the cavity between two neighboring tracks, has been considered. The feasibility of the scaling-up technique for the design of a model with feature height at 1 or 10 mm is discussed.