Abstract: A capacitive mat includes a first set of conductors that function as sensing electrodes applied to a first side of a substrate and a second set of conductors that function as shield electrodes applied to a second side of the substrate. Upper and lower exterior layers are placed over the sets of conductors. The substrate and the exterior layers may be formed from flexible materials. Circuitry in the mat determines a capacitance associated with the conductors at a region of the mat that is associated with an object on the mat. To reduce thickness and improve flexibility, the shield electrodes may be used to determine a ground reference value and use of separate ground electrodes may be omitted. Conductive regions on the mat may be used to couple with adjacent mats, allowing several mats to be easily combined to cover a larger surface.