Ultrasonic touch sensor and system

1. A touch sensor chip, comprising:

an ultrasound sensor layer comprising an array of ultrasonic transducers, wherein the array of ultrasonic transducers comprises a transmitting set of ultrasonic transducers configured for transmitting ultrasound signals and a receiving set of ultrasonic transducers configured for receiving ultrasound reflections associated with transmitted ultrasound signals, wherein the transmitting set of ultrasonic transducers are separate from the receiving set of ultrasonic transducers, wherein the transmitting set of ultrasonic transducers are arranged to surround the receiving set of ultrasonic transducers within the ultrasound sensor layer; and

an integrated circuit layer coupled to the ultrasound sensor layer, wherein the integrated circuit layer comprises circuitry configured for:

driving the array of ultrasonic transducers to generate ultrasound signals;

receiving reflected ultrasound signals using the array of ultrasonic transducers; and

generating an energy signal associated with received reflected ultrasound signals.

2. The chip of claim 1 , wherein the ultrasound sensor layer and the integrated circuit layer are enclosed within a housing couplable to a material layer through which a touch event can be sensed by the ultrasound sensor layer.

3. The chip of claim 2 , wherein an additional sensor is coupled to the integrated circuit layer, wherein the additional sensor is enclosed within the housing, wherein the additional sensor is a thermal sensor, a vibration sensor, or a gyroscope.

4. The chip of claim 1 , wherein the ultrasound sensor layer is formed and wafer bonded to the integrated circuit layer during fabrication.

5. The chip of claim 1 , wherein the ultrasound sensor layer is fabricated directly onto the integrated circuit layer during fabrication.

6. The chip of claim 1 , wherein the transmitting set of ultrasonic transducers comprises a high frequency transmitting subset of ultrasonic transducers and a low frequency transmitting subset of ultrasonic transducers, and wherein the receiving set of ultrasonic transducers comprises a high frequency receiving subset of ultrasonic transducers and a low frequency receiving subset of ultrasonic transducers.

7. The chip of claim 6 , wherein the low frequency transmitting subset of ultrasonic transducers are arranged to surround the low frequency receiving subset of ultrasonic transducers, and the high frequency transmitting subset of ultrasonic transducers are arranged to surround the high frequency receiving subset of ultrasonic transducers.

8. The chip of claim 6 , wherein the high frequency transmitting subset of ultrasonic transducers and the low frequency transmitting subset of ultrasonic transducers generate the ultrasound signals during a touch event.

9. The chip of claim 1 , wherein the integrated circuit layer comprises ultrasound transmitting circuitry and ultrasound receiving circuitry, wherein the ultrasound transmitting circuitry is electrically coupled to the transmitting set of ultrasonic transducers and not electrically coupled to the receiving set of ultrasonic transducers, and wherein the ultrasound receiving circuitry is electrically coupled to the receiving set of ultrasonic transducers and not electrically coupled to the transmitting set of ultrasonic transducers.

10. The chip of claim 1 , wherein the array of ultrasonic transducers are arranged to facilitate beamforming through a material layer through which a touch event can be sensed by the ultrasound sensor layer.

11. The chip of claim 1 , wherein the array of ultrasonic transducers comprises one or more piezoelectric micromachined ultrasonic transducers, one or more capacitive micromachined ultrasonic transducers, one or more integrated bulk piezoelectric transducers, or one or more non-integrated bulk piezoelectric transducers.