Multiplexer for a piezo ceramic identification device

A multiplexer for a biometric apparatus including a sensor coupled to a processor, the sensor having at least twenty five thousand piezo ceramic elements arranged in a two-dimensional array and spaced at a pitch equal to or less than approximately one hundred microns, each of the piezo ceramic elements having a first end and a second end, the multiplexer comprising:

• a plurality of first conductors coupled to the first ends of piezo ceramic elements in corresponding rows;
• a plurality of first switches each of which is coupled to a respective one of the first conductors;
• a plurality of second conductors coupled to the second ends of piezo ceramic elements in corresponding columns;
• and
• a plurality of second switches each of which is coupled to a respective one of the second conductors,
• wherein the first conductors are approximately orthogonal to the second conductors, and
• wherein the first switches are controlled to couple a signal output from an output port of the signal generator to a particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements, and
• wherein the second switches are controlled to couple a signal associated with the particular piezo ceramic element of the at least twenty five thousand piezo ceramic elements to an input port of the processor.