A two-dimensional capacitive sensor device comprises a sensor substrate with a plurality of wedge shaped sensor cells arranged in a single-layer circular pattern proximal to the substrate. The plurality of wedge shaped sensor cells are arranged in a rotationally symmetric pattern about a center of the single-layer circular pattern. A sensor cell of the plurality of wedge shaped sensor cells comprises a first sensor electrode and a second sensor electrode separated by a border. The first and second sensor electrodes are configured for detecting changes in capacitance caused by one or more input objects. The first and second sensor electrodes become substantially thinner in width approaching the center of the single-layer circular pattern than at a distance further from the center. A sensor circuitry is communicatively coupled with the sensor electrodes of the sensor cell and the sensor circuitry is configured to interpret the changes in capacitance.