A contact sensor apparatus, the sensor comprising: a first insulative layer; a second insulative layer; a first resistor strip on the first insulative layer; a second resistor strip on the second insulative layer; a plurality of first conductive traces provided on the first insulative layer and electrically connected to the first resistor strip; and a plurality of second conductive traces provided on the second insulative layer and electrically connected to the second resistor strip; wherein the first insulative layer and second insulative layer face each other such that the plurality of first conductive traces face the plurality of second conductive traces with each of the first conductive traces extending across the plurality of second conductive traces and each of the second conductive traces extending across the plurality of first conductive traces thereby forming an array of points of intersection of the first and second conductive traces (102, 202), wherein the first insulative layer and second insulative layer are spaced apart such that there is no electrical contact between the plurality of first and second conductive traces (102, 202) when a contact is not applied to the contact sensor, and wherein when a contact is applied there is an electrical contact between at least one of each of the plurality of first and second conductive traces (102, 202) in a region of the contact, wherein when the contact is applied to the apparatus, the apparatus is configured to determine the dimensions of the contact as projected to the first and second resistor strips by measuring an electrical quantity across the first and second resistor strips, wherein the electrical quantity includes a resistance, a voltage or a current. a first insulative layer; a second insulative layer; a first resistor strip on the first insulative layer; a second resistor strip on the second insulative layer; a plurality of first conductive traces provided on the first insulative layer and electrically connected to the first resistor strip; and a plurality of second conductive traces provided on the second insulative layer and electrically connected to the second resistor strip; wherein the first insulative layer and second insulative layer face each other such that the plurality of first conductive traces face the plurality of second conductive traces with each of the first conductive traces extending across the plurality of second conductive traces and each of the second conductive traces extending across the plurality of first conductive traces thereby forming an array of points of intersection of the first and second conductive traces (102, 202), wherein the first insulative layer and second insulative layer are spaced apart such that there is no electrical contact between the plurality of first and second conductive traces (102, 202) when a contact is not applied to the contact sensor, and wherein when a contact is applied there is an electrical contact between at least one of each of the plurality of first and second conductive traces (102, 202) in a region of the contact, wherein when the contact is applied to the apparatus, the apparatus is configured to determine the dimensions of the contact as projected to the first and second resistor strips by measuring an electrical quantity across the first and second resistor strips, wherein the electrical quantity includes a resistance, a voltage or a current.