Droplet ejector with oscillating tapered aperture

• US 7,108,197 B2
• Filed: 05/09/2005
• Issued: 09/19/2006
• Est. Priority Date: 04/24/1991
• Status: Expired due to Fees

• Current Assignee: Novartis Pharma AG (Novartis Ag)
• Original Assignee: Aerogen, Inc. (Nektar Therapeutics)
• Inventors: Ivri, Yehuda
• Primary Examiner(s): Ganey, Steven J.
• Application Number:
  US11/125,812
• Publication Number:
  US 20050263608A1
• Time in Patent Office: 498 Days
• Field of Search: 239/4, 239/102.1, 239/102.2, 239/548, 239/552, 239/556, 239/601, 347/20, 347/47, 347/54, 347/68
• US Class Current: 239/4
• CPC Class Codes: A61M 11/005 using ultrasonics spraying or atomising liquids using ultrasonic vibrations in general B05B17/06
• CPC Class Codes: A61M 11/006 operated by applying mechanical pressure to the liquid to be sprayed or atomised
• CPC Class Codes: A61M 15/025 Bubble jet droplet ejection devices
• CPC Class Codes: A61M 2205/3306 Optical measuring means
• CPC Class Codes: B05B 12/08 responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
• 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 17/0669 Excitation frequencies
• CPC Class Codes: B05B 17/0676 Feeding means
• CPC Class Codes: B05B 17/0684 Wicks or the like
• CPC Class Codes: B41J 2/025 by vibration
• CPC Class Codes: B41J 2/04 generating single droplets or particles on demand
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate

Abstract

A fluid injection device for ejecting fluid droplets in response to electrical signals comprises an oscillating surface that has one or more tapered apertures, each aperture having a first and second opening. The first opening of each aperture is larger than the second opening. The first opening is in surface tension contact with the fluid to be ejected. The fluid interaction with the tapered aperture wall creates cycles of fluid compression and decompression inside the aperture, causing fluid to be drawn from the large opening and ejected out the small opening of the aperture. The device includes a fluid supply nozzle that transports fluid to the oscillating surface at the large opening of the apertures. A discharge valve controls the fluid supply. An electronic wave generator induces oscillation in the tapered aperture containing surface. The device is used to great advantage for fluid atomization and fluid spray.

Claims

1. A droplet ejector device, comprising:

a vibratable curved member having a perimeter area, a center area, a rear surface and a front surface, and a plurality of tapered apertures that taper inwardly from the rear surface to the front surface;

a container that is configured to store a liquid that is to be supplied to the rear surface of the vibratable curved member wherein when the liquid is at the rear surface the liquid is no greater than atmospheric pressure;

a vibratory element coupled to the vibratable curved member at the perimeter area, wherein the vibratory element is actuatable to vibrate the vibratable curved member, and wherein vibration of the vibratable curved member is configured to eject liquid droplets from the front surface when liquid is supplied from the container to the rear surface.

2. A device as in claim 1, wherein the vibratory element comprises a piezoceramic.

3. A device as in claim 1, wherein the apertures taper from about 0.006 inch to about 0.0025 inch.

4. A device as in claim 1, wherein the vibratory element is configured to vibrate the vibratable curved member at a frequency of about 60,000 Hz or greater.

5. A method for ejecting liquid droplets, the method comprising:

providing a vibratable curved member having a perimeter area, a center area, a rear surface and a front surface, and a plurality of tapered apertures that taper inwardly from the rear surface to the front surface;

supplying an amount of liquid to the rear surface of the vibratable curved member wherein when the liquid is at the rear surface the liquid is at no greater than atmospheric pressure;

vibrating the vibratable curved member with a vibratory element that is coupled at the perimeter area while the liquid is supplied to the rear surface to cause liquid droplets to be ejected from the front surface.

6. A method as in claim 5, wherein the liquid is supplied to the rear surface from a container.

7. A method as in claim 5, further comprising controlling the amount of liquid supplied to the rear surface.

8. A method as in claim 5, further comprising vibrating the vibratable curved member with a piezoceramic at a frequency of about 60,000 Hz or greater.

9. A method as in claim 5, wherein the apertures taper from about 0.006 inch to about 0.0025 inch.

10. A method as in claim 5, further comprising vibrating the vibratable curved member under different pressure conditions.

11. A method as in claim 5, wherein the liquid comprises a medicament.

12. A droplet ejector device, comprising:

a vibratable curved member having a perimeter area, a center area, a rear surface and a front surface, and a plurality of tapered apertures that taper inwardly from the rear surface to the front surface;

a container that is configured to store a liquid that is to be supplied to the rear surface of the vibratable curved member wherein when the liquid is at the front surface the liquid is at no greater than atmospheric pressure;

a vibratory element coupled to the vibratable curved member at the perimeter area, wherein the vibratory element is actuatable to vibrate the vibratable curved member, and wherein vibration of the vibratable curved member is configured to eject liquid droplets from the front surface when liquid is supplied from the container to the rear surface; and

an intermediary member that is coupled to the vibratable curved member, and wherein the vibratory element is also coupled to the intermediary member.