Ultrasonic authenticating button

1. An ultrasonic button, comprising:

an ultrasonic transmitter configured to transmit an ultrasonic wave;

a piezoelectric receiver layer configured to receive a reflected wave of the ultrasonic wave;

a platen layer configured to protect the ultrasonic transmitter and the piezoelectric receiver layer;

a first matching layer configured to match an acoustic impedance of the platen layer with an acoustic impedance of ridges of a finger, wherein the first matching layer has an acoustic impedance approximately equal to a geometric mean of the acoustic impedance of the ridges of the finger and the acoustic impedance of the platen layer;

an ultrasonic sensor array configured to detect the finger using the reflected wave; and

a haptic device, wherein the ultrasonic sensor array and the haptic device are mechanically coupled to each other, and wherein the ultrasonic sensor array and the haptic device are configured to provide a haptic feedback.

2. The ultrasonic button of claim 1 , further comprising:

a second matching layer configured to match the acoustic impedance of the platen layer with an acoustic impedance of the piezoelectric receiver layer, wherein the second matching layer has an acoustic impedance approximately equal to a geometric mean of the acoustic impedance of the piezoelectric receiver layer and the acoustic impedance of the platen layer.

3. The ultrasonic button of claim 1 , wherein the ultrasonic sensor array comprises a TFT-based sensor array or a silicon-based sensor array.

4. The ultrasonic button of claim 3 , wherein the ultrasonic sensor array is configured to generate fingerprint image information of the finger using the reflected wave to authenticate a user; and wherein the fingerprint image information is used in enrollment, authentication, delivery of a prescribed medication to an authenticated user, or performance of a button function.

5. The ultrasonic button of claim 1 further comprising:

an electromechanical switch configured to detect a force being applied to the ultrasonic button, wherein the ultrasonic sensor array and the electromechanical switch are mechanically coupled to each other, and wherein the ultrasonic sensor array and the electromechanical switch are configured to provide at least a user interface.

6. The ultrasonic button of claim 1 further comprising:

a capacitive sense ring, wherein the capacitive sense ring is located in a trench of the platen layer, and wherein the ultrasonic sensor array and the capacitive sense ring are communicatively coupled to each other, and wherein the ultrasonic sensor array and the capacitive sense ring are configured to provide at least a user interface.

7. The ultrasonic button of claim 1 , wherein the platen layer further comprises:

an exterior recessed pocket configured to indicate a location of the ultrasonic button to a user, an interior recessed pocket configured to provide space for the ultrasonic sensor array, a cutout in the platen layer, a cutout with a recessed shoulder region in the platen layer, or a combination thereof.

8. The ultrasonic button of claim 1 , wherein the platen layer is made of at least one of sapphire, gorilla glass, aluminum, stainless steel, a metal alloy, polycarbonate, a polymeric material, or a metal-filled plastic.

9. The ultrasonic button of claim 2 , wherein the first matching layer or the second matching layer is made of at least one of an epoxy-based hard coating with a filler, an acrylic-based hard coating with a filler, an epoxy-based hard coating with glass, an acrylic-based hard coatings with glass, or a glass layer.

10. A method of detecting a finger using an ultrasonic button, wherein the ultrasonic button comprises an ultrasonic transmitter, a piezoelectric receiver layer, and an ultrasonic sensor array, comprising:

transmitting an ultrasonic wave from the ultrasonic transmitter, wherein the ultrasonic wave passes through a platen layer and a first matching layer;

matching an acoustic impedance of the platen layer with an acoustic impedance of ridges of the finger at the first matching layer, wherein the first matching layer has an acoustic impedance approximately equal to a geometric mean of the acoustic impedance of the ridges of the finger and the acoustic impedance of the platen layer;

receiving a reflected wave of the ultrasonic wave at the piezoelectric receiver layer, wherein the reflected wave passes through the platen layer and the first matching layer;

detecting the finger based on the reflected wave using the ultrasonic sensor array; and

providing a haptic feedback to the finger with the ultrasonic sensor array and a haptic device, wherein the ultrasonic sensor array and the haptic device are mechanically coupled to each other.

11. The method of claim 10 , further comprising:

matching the acoustic impedance of the platen layer with an acoustic impedance of the piezoelectric receiver layer at a second matching layer, wherein the second matching layer has an acoustic impedance approximately equal to a geometric mean of the acoustic impedance of the piezoelectric receiver layer and the acoustic impedance of the platen layer.

12. The method of claim 10 , wherein the ultrasonic sensor array comprises a TFT-based sensor array or a silicon-based sensor array.

13. The method of claim 12 , further comprising:

generating fingerprint image information of the finger using the reflected wave to authenticate a user at the ultrasonic sensor array; and

using the fingerprint image information in enrollment, authentication, delivery of a prescribed medication to an authenticated user, or performance of a button function.

14. The method of claim 10 , wherein the ultrasonic button further comprises:

an electromechanical switch configured to detect a force being applied to the ultrasonic button, and wherein the ultrasonic sensor array and the electromechanical switch are mechanically coupled to each other, and wherein the ultrasonic sensor array and the electromechanical switch are configured to provide at least a user interface.

15. The method of claim 10 , wherein the ultrasonic button further comprises:

a capacitive sense ring, wherein the capacitive sense ring is located in a trench of the platen layer, and wherein the ultrasonic sensor array and the capacitive sense ring are communicatively coupled to each other, and wherein the ultrasonic sensor array and the capacitive sense ring are configured to provide at least a user interface.

16. An ultrasonic button, comprising:

means for transmitting an ultrasonic wave; wherein the ultrasonic wave passes through a platen layer and a first matching layer;

means for matching an acoustic impedance of the platen layer with an acoustic impedance of ridges of a finger;

means for receiving a reflected wave of the ultrasonic wave, wherein the reflected wave passes through the platen layer and the first matching layer, wherein the first matching layer has an acoustic impedance approximately equal to a geometric mean of the acoustic impedance of the ridges of the finger and the acoustic impedance of the platen layer;

means for detecting the finger based on the reflected wave; and

means for providing a haptic feedback to the finger, wherein the means for receiving a reflected wave of the ultrasonic wave and the means for providing a haptic feedback to the finger are mechanically coupled to each other.

17. The ultrasonic button of claim 16 , further comprising:

means for matching the acoustic impedance of the platen layer with an acoustic impedance of a piezoelectric receiver layer.

18. The ultrasonic button of claim 16 , further comprising:

means for generating fingerprint image information of the finger using the reflected wave to authenticate a user; and

means for using the fingerprint image information in enrollment, authentication, delivery of a prescribed medication to an authenticated user, or performance of a button function.