Computation devices and artificial neurons based on nanoelectromechanical systems

A monolithic ultrasonic fingerprint scanner using piezoelectric transducers, comprising:

• a substrate comprising a semiconductor material;
• an acoustic matching layer, coupled to a backside of the substrate, to provide a surface for a finger to make contact;
• a CMOS active layer attached directly on a topside of the substrate;
• and
• an array of piezoelectric transducers, solidly arranged over the CMOS active layer, wherein each of the piezoelectric transducers is operable to generate an incident acoustic wave or an incident acoustic pulse having one or more frequencies of at least 1 GHz that propagates through the substrate and toward the acoustic matching layer, wherein each of the piezoelectric transducers is operable to receive reflected acoustic waves or reflected acoustic pulses reflected from an object being detected at the surface, wherein the substrate lies below the piezoelectric transducers, wherein the acoustic matching layer lies below the substrate and above the object being detected, wherein the surface lies at a bottom of the acoustic matching layer,
• wherein the CMOS active layer includes a CMOS die in electrical communication with the array of piezoelectric transducers to receive and process outputs from the piezoelectric transducers produced in response to the reflected acoustic waves or the reflected acoustic pulses.