1. A multi-touch surface apparatus comprising: a substrate; a two-dimensional array of sensing electrodes arranged on the substrate; at least one power supply connectable to a plurality of the sensing electrodes along a first direction of the two-dimensional array; at least one capacitor connectable to a plurality of the sensing electrodes along a second direction of the two-dimensional array, the at least one capacitor arranged to accumulate charge transferred from the at least one power supply via one of the plurality of sensing electrodes.