Systems and methods of detecting, identifying, and classifying objects positioned on a shelf are provided. In one exemplary embodiment, a sensor pad comprises a plurality of electrical contacts disposed in the pad as a matrix of rows and columns of electrical contacts. Further, each contact corresponds to a different surface area of the pad and has a first electrical conductor positioned on a first layer and a second electrical conductor positioned opposite to the first conductor on a second layer. Also, at least one of the first and second conductors is operable to vary in resistance or capacitance based on an amount of pressure applied to that conductor. In addition, each contact is configured to enable an electrical connection between the first and second conductors with a resistance or capacitance that varies based on an amount of pressure applied to a corresponding area of the pad when an object is positioned on that pad.