Method and system for multi-mode mechanical resonator
View Patent ↗Provided is a fingerprint sensor including one or more mechanical devices for capturing the fingerprint. The resonators are configured to be mechanically damped based upon an applied load.
1. A sensor, comprising:
one or more mechanical devices for capturing an image of a fingerprint, each device including a matrix of pillars;
wherein a pillar of interest within the matrix is (a) only connected to diagonally adjacent pillars and (b) devoid of a connection to vertically and horizontally adjacent pillars.
2. The sensor of claim 1 , wherein the pillars are formed of at least one of resonators and oscillators.
3. The sensor of claim 1 , wherein a q factor of individual pillars within the matrix is optimized by adjusting a distance between pillars in accordance with a quarter shear wavelength at an operating wavelength.
4. The sensor of claim 3 , wherein the q factor can be improved by reducing an acoustic impedance of matrix material, the reducing being facilitated by at least one of (i) reducing a density of the matrix material and (ii) reducing a stiffness of the matrix material.
5. The sensor of claim 4 , wherein the sensor is configured to be excited via piezo-electric, magnetic, or electrical forces.
6. The sensor of claim 5 , wherein the fingerprint image is captured via scanning a fingerprint structure in a manner that includes at least one from the group including mechanically and electronically.
7. The sensor of claim 6 , wherein damping is observed using at least one from the group including voltage, current, impedance, displacement, stress, strain, and optical reflection.
8. The sensor of claim 7 , further comprising a matching layer configured for reducing a difference in acoustic impedance between the sensor and a structure of the finger.
9. The sensor of claim 7 , wherein the matching layer includes a predetermined thickness and acoustic impedance.
10. The sensor of claim 1 , wherein the pillar of interest is electrically connected to the diagonally adjacent pillars.
11. The sensor of claim 1 , wherein the vertically and horizontally adjacent pillars are inactive in relation to the pillar of interest.
12. The sensor of claim 1 , wherein the vertically and horizontally adjacent pillars provide only passive reflection in relation to the pillar of interest.
13. The sensor of claim 1 , wherein the pillars are of a square cross-section.
14. The sensor of claim 13 , wherein the pillar of interest is surrounded by four pillars face to face and is devoid of a connection to the four pillars.
15. A method comprising:
capturing an image of a fingerprint using one or more mechanical devices, each device including a matrix of pillars;
wherein a pillar of interest within the matrix is (a) only connected to diagonally adjacent pillars and (b) devoid of a connection to vertically and horizontally adjacent pillars; and
monitoring excitation of pillars adjacent to a pillar of interest, the adjacent pillars being (a) only diagonally connected to the pillar of interest and (b) devoid of a vertical or horizontal connection to the pillar of interest.