Laminar flow droplet generator device and methods of use

• US 9,463,486 B2
• Filed: 05/14/2013
• Issued: 10/11/2016
• Est. Priority Date: 05/14/2012
• Status: Active Grant

• Current Assignee: Eyenovia Inc.
• Original Assignee: Eyenovia Inc.
• Inventors: Wilkerson, Jonathan Ryan, Lynch, Iyam, Germinario, Louis Thomas, Hunter, Charles Eric
• Primary Examiner(s): Ganey, Steven J
• Application Number:
  US13/893,776
• Publication Number:
  US 20130334335A1
• Time in Patent Office: 1,246 Days
• Field of Search: 239/102.1, 239/102.2, 239/338, 239/552, 239/104, 239/120, 239/596, 239/601, 128/200.14, 128/200.16, 604/298
• US Class Current: 1/1
• CPC Class Codes: A61F 9/0008 Introducing ophthalmic products into the ocular cavity or retaining products therein putting in contact lenses A61F9/0061; introducing or retaining media in cavities of the body in general A61M31/00
• CPC Class Codes: A61M 15/0065 Inhalators with dosage or measuring devices A61M15/0028 takes precedence; dosage devices incorporated in aerosol cans B65D83/52
• CPC Class Codes: A61M 15/0085 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: B05B 1/02 designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shapeB05B1/26, B05B1/28, B05B1/34 take precedence
• CPC Class Codes: B05B 1/14 with multiple outlet openings B05B1/02, B05B1/26 take precedence; with strainers in or outside the outlet opening
• CPC Class Codes: B05B 1/28 with integral means for shielding the discharged liquid or other fluent material, e.g. to limit area of spray; with integral means for catching drips or collecting surplus liquid or other fluent material means for any of these purposes, per se, B05B12/16, B05B12/32, B05B14/00
• CPC Class Codes: B05B 15/50 Arrangements for cleaning; Arrangements for preventing deposits, drying-out or blockage; Arrangements for detecting improper discharge caused by the presence of foreign matter
• CPC Class Codes: B05B 17/06 using ultrasonic or other kinds of vibrations
• 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: B05B 17/0661 Transducer materials
• CPC Class Codes: B05B 17/0669 Excitation frequencies
• CPC Class Codes: B05B 7/0012 Apparatus for achieving spraying before discharge from the apparatus
• CPC Class Codes: B06B 1/0651 of circular shape
• CPC Class Codes: F02M 61/1853 Orifice plates

Abstract

A piezoelectric ejector device is provided which is designed to minimize the intake of air into the device upon actuation by providing for laminar flow of the fluid. In an ejector mechanism that includes a generator plate and a piezoelectric actuator operable to directly or indirectly oscillate the generator plate, at a frequency to generate a directed stream of droplets of fluid, the generator plate includes a fluid facing surface, a droplet ejection surface, and a plurality of holes formed through its thickness between the surfaces. The plurality of holes are configured so as to minimize airflow through the plurality of openings from the droplet ejection surface to the fluid facing surface during generation of the directed stream of droplets by configuring the shape of the holes to minimize turbulence.

Claims

1. A device for generating a directed stream of droplets, the device comprising:

a housing;

a reservoir disposed within the housing for receiving a volume of fluid; and

an ejector mechanism in fluid communication with the reservoir and configured to generate the directed stream of droplets of said fluid, the ejector mechanism comprising a generator plate and a piezoelectric actuator;

wherein the generator plate includes a fluid facing surface, a droplet ejection surface, and a plurality of openings formed through its thickness between said surfaces;

wherein the piezoelectric actuator is operable to directly or indirectly oscillate the generator plate, at a frequency to generate the directed stream of droplets of said fluid; and

wherein the plurality of openings of the generator plate have a gradual slope of change from the fluid facing surface to the droplet ejection surface so as to provide an external entry radius of curvature having a circular shape thereby reducing airflow through the plurality of openings from the droplet ejection surface to the fluid facing surface during generation of the directed stream of droplets to provide the fluid with laminar flow as it passes through the openings.

2. The device of claim 1, wherein the intake from the fluid facing surface into each of the openings defines a fluted intake providing a gradual transition from the fluid facing surface into the opening.

3. The device of claim 1, wherein at the droplet ejection surface trench is defined around at least one of the openings.

4. The device of claim 1, wherein the ratio of size of the radius of curvature to the size of the opening at the droplet ejection surface is:

greater than about 2.5, when the opening at the droplet ejection surface is greater than about 40 μ

m, or the ratio is greater than about 5, when the opening at the droplet ejection surface is less than about 40 μ

m.

5. The device of claim 1, wherein each opening defines a fluted intake and a channel that extends to the droplet ejection surface, the channel being configured with sufficient length so as to achieve laminar flow of the fluid prior to the fluid reaching the ejection surface.

6. The device of claim 1, wherein said ejector mechanism further comprises an ejector plate coupled to the generator plate and the piezoelectric actuator, the piezoelectric actuator being operable to oscillate the ejector plate, and thereby the generator plate, at the frequency to generate the directed stream of droplets.

7. The device of claim 6, wherein the ejector plate has a central open region aligned with the generator plate, and the piezoelectric actuator is coupled to a peripheral region of the ejector plate so as not to obstruct the plurality of openings of the generator plate.

8. The device of claim 7, wherein the plurality of openings of the generator plate are disposed in a center region of the generator plate that is uncovered by the piezoelectric actuator and aligned with the central open region of the ejector plate.

9. The device of claim 7, wherein the generator plate has a reduced size relative to the ejector plate, and the size of the generator plate is determined, at least in part, by the area occupied by the center region and the arrangement of the plurality of openings.

10. The device of claim 1, wherein the ejector mechanism is configured to eject the directed stream of droplets such that at least about 75% of the mass of the ejected droplets deposit on the target.

11. The device of claim 1, wherein the ejector mechanism is configured to eject the directed stream of droplets having an average ejected droplet diameter in the range of 20 to 400 microns.

12. The device of claim 1, wherein the ejecting mechanism is configured to eject the directed stream of droplets having an average initial ejected velocity in the range of 0.5 m/s to 10 m/s.