Micromachined two dimensional array of piezoelectrically actuated flextensional transducers

• US 20010035700A1
• Filed: 02/27/2001
• Published: 11/01/2001
• Est. Priority Date: 09/20/1995
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Percin, Gokhan, Khuri-Yakub, Butrus Thomas
• Granted Patent: US 6,445,109 B2
• Time in Patent Office: Days
• US Class Current: 310/324
• CPC Class Codes: B05B 17/0607 generated by electrical means, e.g. piezoelectric transducers
• CPC Class Codes: B05B 17/0646 Vibrating plates, i.e. plates being directly subjected to the vibrations, e.g. having a piezoelectric transducer attached thereto
• CPC Class Codes: B41J 2/14201 Structure of print heads with piezoelectric elements
• CPC Class Codes: B41J 2/1607 Production of print heads with piezoelectric elements B41J2/1606, B41J2/162 take precedence
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1634 laser machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2002/1437 Back shooter
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate
• CPC Class Codes: Y10S 977/837 Piezoelectric property of nanomaterial
• CPC Class Codes: Y10S 977/86 Scanning probe structure
• CPC Class Codes: Y10S 977/869 Optical microscope
• CPC Class Codes: Y10S 977/872 Positioner
• CPC Class Codes: Y10S 977/887 Nanoimprint lithography, i.e. nanostamp

Abstract

A transducer suitable for ultrasonic applications, fluid drop ejection and scanning force microscopy. The transducer comprises a thin piezoelectric ring bonded to a thin fully supported clamped membrane. Voltages applied to said piezoelectric ring excite axisymmetric resonant modes in the clamped membrane.

Claims

1. A two-dimensional array of piezoelectrically actuated flextensional fluid drop ejectors comprising:

a plurality of membranes having a selected area, said membranes including one or more apertures,

a support structure engaging the outer edges of each of said membranes to flexibly support the membranes, said support structure and said membranes configured to form fluid reservoirs so that fluid to be ejected is in contact with said membranes,

a piezoelectric transducer carried on one surface of each of said membranes surrounding said aperture, said transducer including a body of piezoelectric material having first and second spaced opposite surfaces,

conductive contacts on the opposite surfaces of said body of piezoelectric material for each of said transducers for applying a voltage across said piezoelectric material to cause flextensional movement of said body of piezoelectric material whereby the associated membrane flexes responsive to applied voltage whereby the application of an ac voltage of predetermined frequency causes said membrane to resonate, and

conductive means for applying said voltages across selected piezoelectric transducer to selectively bring membranes into resonance to selectively eject droplets perpendicular to the surface of said membranes through said orifice.

2. A piezoelectrically actuated flextensional transducer as in

claim 1

in which the membranes are silicon nitride.

3. A piezoelectrically actuated flextensional transducer as in

claim 1

in which said membranes are polysilicon.

4. A piezoelectrically actuated flextensional transducer as in

claim 1

in which said support structure is silicon oxide.

5. A piezoelectrically actuated flextensional transducer as in

claim 1

in which said membranes are circular and said piezoelectric transducers are annular.

6. A piezoelectrically actuated flextensional transducer as in

claim 1

in which the membranes merge to form a single membrane with multiple piezoelectric transducers.

7. A piezoelectrically actuated flextensional transducer as in claims 1, 2, 3, 4, or 5 in which the apertures are spaced apart a distance less than 100 μ

m.

8. A piezoelectrically actuated flextensional transducer as in claims 1, 2, 3, 4, or 5 in which the apertures are spaced apart a distance between 50 and 100 μ

m.