US Patent 9766742 Contact sensor

A contact sensor apparatus comprises: a first insulative layer (100); a second insulative layer (200); a first resistor strip (101) on the first insulative layer; a second resistor strip (201) on the second insulative layer; a plurality of first conductive traces (102) provided on the first insulative layer and electrically connected to the first resistor strip; and a plurality of second conductive traces (202) provided on the second insulative layer and electrically connected to the second resistor strip. 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. 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 when a contact is not applied to the contact sensor. 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 in a region of the contact.