Droplet injector with treated surface

Abstract

The invention provides a droplet injector having a treated surface. A droplet delivery device includes an ejector mechanism having an ejector web or similar substrate with apertures that is treated by one or more of coating, roughening, metal layer deposition, and laser ablation to provide desired droplet yield and size, e.g., in inhaled aerosols from the device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to Provisional Patent Application No. 63 / 318,202, entitled “DROPLET EJECTOR WITH OLEOPHOBICCOATING,” filed on March 9, 2022, Provisional Patent Application No. 63 / 323,770, entitled “ROUGHENED DROPLETEJECTOR SURFACE AND COATINGS,” filed on March 25, 2022, and Provisional Patent Application No. 63 / 346,794, entitled “POLYMER DROPLET EJECTOR WITH SPUTTERED COATING SURFACE,” filed on May 27, 2022, all of which are incorporated herein by reference in their entirety. Technical Field

[0002] The present disclosure relates to droplet generating devices, for example, to generate aerosols having a composition for inhalation, for example, through the mouth and nose. Background Art

[0003] The use of droplet generating devices for delivering substances to the respiratory system is an area of ​​great interest. A major challenge is to provide a device that delivers accurate, consistent and verifiable amounts of substances in droplet sizes suitable for successful delivery of the substance to target areas of the respiratory system.

[0004] The droplet delivery device includes an ejector mechanism with a mesh, orifice plate, or similar substrate having holes of a desired size and producing a desired surface contact angle, which produces droplets from the liquid passing through the mesh when a powered actuator acts on the liquid and the ejector mechanism. In some devices, the membrane can be oscillated by a powered actuator to push the liquid through the mesh and produce droplets ("push mode"), while in other devices, the actuator can be directly coupled to oscillate the mesh to produce droplets. Examples of devices including such an ejector mechanism having a substrate with holes are described in the following documents: U.S. patent application publication number US2022 / 0401661, entitled “DELIVERY DEVICE WITH PUSH EJECTION”, published on December 22, 2022, international publication number WO 2020 / 264501, entitled “DELIVERY OF SMALL DROPLETS TO THE RES-PIRATORY SYSTEM VIA ELECTRONIC BREATH ACTUATED DROPLET DELIVERY DEVICE”, published on December 30, 2020, and international publication number WO 2020 / 264501, entitled “ULTRASONIC BREATH ACTUATED RESPIRATORY DROPLET DELIVERY DEVICE AND METHODS OF USE”, published on November 12, 2020. 2020 / 227717, all of which are incorporated herein by reference in their entirety, including the incorporation of such publications and patent application documents cited by reference and incorporated or relied upon in the cited disclosure.

[0005] Droplet delivery devices can be used to facilitate inhalation of a wide variety of therapeutic substances (such as drugs and pharmaceutical substances) and non-therapeutic substances (such as nicotine). Along with such substances, it may be desirable to include flavoring compositions, which are typically oil-based, which presents a challenge to generating droplets from droplet delivery devices that enable the desired inhalation, as the liquid composition may have variable water and oil content that affects droplet formation and interaction through the web of the ejector mechanism. Summary of the invention Summary of the Invention

[0006] In embodiments, the present invention includes an injector web, and in some embodiments, other fluid contacting components of the injector, that have been treated to enhance droplet generation and achieve smaller droplet size in aerosols that are inhaled into the nose or mouth. In one embodiment, the injector components may be treated with an oleophobic coating that reduces adhesion of the oil-containing composition to the injector fluid contacting components and the injector web.

[0007] In further embodiments, the injector web, and in some cases other injector components that contact the fluid composition, may be intentionally roughened prior to application of the oleophobic coating to further reduce adhesion between the additive solution and the injector web and components and maintain a higher surface contact angle for desired droplet formation from the solution / formulation.

[0008] In further embodiments, various coatings and combinations of coatings may be applied following roughening of the injector web, and possibly other injector components that contact the fluid composition, including hydrophobic coatings (repel water), oleophobic coatings (repel oil or non-polar liquids), and / or anti-grease coatings (repel lipids or other non-polar solvents).

[0009] In some embodiments, different ejector materials and different coatings may be used in varying combinations to facilitate better ejection of droplets from the substance to be aerosolized.

[0010] In one embodiment of the present invention, a polymer ejector mesh having holes formed by laser ablation can be provided with a sputtered metal surface, such as palladium and gold metal, on top of the polymer mesh material. The metal sputtering adds stiffness to the polymer ejector plate, resulting in the unexpected effect of increased droplet ejection from the droplet ejector device.

[0011] In further embodiments of the invention, laser ablation and / or nanomolding of various polymeric materials can be used to create an injector substrate, such as a mesh or orifice plate. In certain embodiments, polysulfone, polyimide, polyimide coated with FEP, FEP, PEEK, PTFE, PVDF, and PFA provide advantageous materials for such laser ablation or nanomolding of injector components. Detailed instructions

[0012] In one embodiment of the invention, a droplet delivery device with a powered transducer includes an ejector mechanism having a mesh or similar substrate with holes of a predetermined size and shape. The container of the device supplies a liquid composition to the ejector mechanism to produce droplets of a desired size for inhalation.

[0013] In one embodiment, the liquid composition supplied to the ejector mechanism and the mesh is a nicotine formulation having 0-20% propylene glycol (PG), vegetable glycerin (VG) and glycerin (VG in purer form). These oils (typically used to provide flavoring) result in lower contact angles through a mesh having a hydrophobic coating, as described in the incorporated disclosures confirmed in the relevant disclosures section. For example, tests have shown that the contact angle decreases from 111.3 to 102.8 when a 10% VG solution is used. Therefore, the contact angle should decrease with increasing amounts of the above additives. In addition, the contact angle should decrease depending on which additive is used, i.e. PG>>>glycerin>VG.

[0014] In order to help minimize the adhesion between the additive solution and the injector material (fluid contact part) and the injector mesh, it is preferred to use an oleophobic and / or hydrophobic coating or a combination of coatings so that droplets desired for inhalation are produced. In particular, in one embodiment, an oleophobic coating is used, which allows aqueous solutions and aqueous solutions containing small hydrocarbon segment additives to have a contact angle greater than 110 degrees. In one embodiment, a hydrophobic / oleophobic monolayer can be used. In embodiments of the present invention, good candidates for achieving this higher contact angle include the use of fluorocarbons or organofluorine compounds. Some examples of these perfluorinated compounds may include poly- and perfluoroalkyl substances (PFAS).

[0015] In some embodiments, a "universal" type oleophobic coating can be used to coat injector webs and injector components that come into contact with oil-based compositions. For example, a coating comprising a mixture of 1H, 1H, 2H, 2H-perfluorohexyltrichlorosilane (PFTS) and n-butyl cyanoacrylate (n-BCA), combined in a dichloropentafluoropropane solution, as described in the following, can be used in embodiments of the present invention: https: / / cen.acs.org / materials / coatings / Fluorinated-coating-utterly- repellen t / 96 / i42 (Incorporated herein by reference.) Other coatings in other embodiments may also include a trichlorosilane head group on a fluorinated hydrocarbon.

[0016] In some embodiments of the present invention, intentionally roughening the surfaces of the injector web, and possibly other injector components that contact the oil-containing formulation in other embodiments, provides better adhesion of the oleophobic coating to the desired surface. For example, it is expected that an oleophobic coated surface without roughening will have a contact angle of about 104°, while roughening the surface and then coating the surface (i.e., a better-adhering coating) can provide a contact angle of 115°.

[0017] In various embodiments, roughening of the desired surface (e.g., injector webs and / or other injector components) may include roughening palladium nickel with oxygen plasma etching, argon sputter etching, ion bombardment, abrasive / roughening beads (e.g., alumina and zirconia), other chemical etching techniques, etc. The roughened surface is then coated with an oleophobic (and preferably hydrophobic) coating to generate the desired droplets from the liquid formulation of the droplet delivery device.

[0018] In other embodiments, various coatings and combinations of coatings may be applied following roughening of the injector web, and possibly other injector components that contact the fluid composition, including hydrophobic coatings (repel water), oleophobic coatings (repel oil or non-polar liquids), and / or anti-grease coatings (repel lipids or other non-polar solvents).

[0019] In embodiments where one or more coatings are applied to the roughened surface of an injector web or component, it is preferred to apply the coating with sufficient thickness to completely cover the surface peaks and valleys formed by the roughening so that the coated surface is ultimately smooth because the one or more coatings bond to the peaks and valleys.

[0020] In certain embodiments, a combination of all three hydrophobic, oleophobic, and anti-grease coatings (particularly using fluorocarbons and / or halogenated silanes) may be applied to a roughened ejector web and / or ejector surface that contacts the fluid composition of the droplet delivery device. In other words, after the desired ejector surface (e.g., ejector web / plate) has been roughened, a coating that is anti-grease / oleophobic in addition to being hydrophobic may be applied. In some embodiments, the above coatings or combined coatings may not repel liquids, but do not provide / lack attraction / adhesion between the ejector surface and the liquid composition.

[0021] In further embodiments where an injector mesh or similar substrate having apertures includes one or more coatings, the one or more coatings are also specifically applied to the holes or apertures. Different coatings may also be applied to different surfaces of an injector mesh or component, such as one face or surface including a first coating type and an opposing face or surface including a second coating type. In some embodiments, a third coating type may be further applied to the apertures or apertures of an injector mesh or component.

[0022] In certain embodiments, one or more coatings may be applied to the ejector web or components to increase slip to reduce the shear zone of the droplets generated by the ejector mechanism. Depending on the type of fluid generating the droplets, the use of different coatings or combinations of coatings on the ejector web, ejector substrate apertures and / or components may provide better control of the shear zone and keep the droplet size not too large or too small for the intended application of a particular type of droplet.

[0023] In some embodiments, when a metal (such as palladium or gold) is deposited on the surface of the ejection plate or component by using sputtering, evaporative deposition or any other form of deposition, the polymer ejection plate will improve the droplet ejection results. Coatings (such as hydrophobic and oleophobic coatings and combinations thereof) can also be optionally added to the polymer ejection plate after metal deposition to provide the desired contact angle and further improved droplet ejection. Roughening of the deposited metal surface can also be implemented in certain embodiments and is optionally used in combination with one or more other coatings (such as oleophobic and / or hydrophobic coatings). In various embodiments of the present invention, the metal surface deposited on the polymer mesh can provide better adhesion of the surface coating. The metal deposited on the surface of the polymer mesh has a higher Young's modulus than the underlying polymer material, so the sputtered / deposited metal layer on the polymer material makes the orifice plate more rigid. In an embodiment of the present invention, the orifice plate (i.e., the ejector mesh / ejector plate) has holes (micrometer scale) formed by laser ablation, and the metal layer (nanometer scale) sputtered onto the polymer ejector plate provides a metal surface layer without interfering with the holes and the liquid passing therethrough for forming droplets on the ejector plate. In some embodiments, the surface of the polymer jetting plate may be roughened and the metal layer deposited onto the roughened surface.

[0024] In some embodiments, the polymer mesh with holes formed by laser ablation may include polymer materials such as polymethyl methacrylate, polyetherketone, polyetherimide, polyvinylidene 1,1-difluoride, ultra-high molecular weight polyethylene, polytetrafluoroethylene (PTFE), etc. In some embodiments, the sputtered or deposited metal layer on the polymer mesh may include a thin layer of precious metals such as gold (Au), palladium (Pd), platinum (Pt), silver (Ag), and precious metal alloys (e.g., sputtered with a thickness of about 30 to about 150 nm, about 60 nm to about 100 nm, about 30 nm, about 60 nm, about 80 nm, about 100 nm, etc.). In embodiments of the present invention, palladium was found to be a preferred deposited / sputtered layer on the polymer. For example, the size range of the pores in the orifice plate (e.g., formed by laser ablation) may be 1 micron to 6 microns, 2 microns to 5 microns, 3 microns to 5 microns, 3 microns to 4 microns, and similar desired small micron size ranges.

[0025] In further embodiments of the invention, laser ablation and / or nanomolding of various polymeric materials can be used to create an injector substrate, such as a mesh or orifice plate. In certain embodiments, polysulfone, polyimide, polyimide coated with fluorinated ethylene propylene (FEP), fluorinated ethylene propylene (FEP), polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE), polyvinylidene fluoride or polyvinylidene fluoride (PVDF), and perfluoroalkoxyalkanes (PFA) provide advantageous materials for such laser ablation or nanomolding of injector components.

[0026] In one aspect of the present invention, the droplet delivery device comprises an ejector comprising a polymer mesh having holes and a deposited metal layer on the polymer mesh. In one embodiment, the metal layer is sputtered onto the polymer mesh, but other deposition methods are also included for depositing the metal layer on the mesh of the present invention.

[0027] In a further aspect, the apertures of the droplet delivery device are formed by laser ablation.

[0028] In a further aspect, the metal layer deposited on the injector mesh of the present invention comprises one or more of gold, palladium, platinum and silver.

[0029] In a further aspect, the metal layer deposited on the injector web of the present invention comprises one or more precious metal alloys.

[0030] In a further aspect, the sparger web of the present invention comprises one or more of polymethyl methacrylate, polyetheretherketone, polyetherimide, polyvinylidene fluoride, ultra high molecular weight polyethylene, polysulfone, polyimide, fluorinated ethylene propylene, perfluoroalkoxyalkane, and polytetrafluoroethylene.

[0031] In aspects of the invention, the polymer network is nanomolded.

[0032] In another aspect of the invention, an oleophobic or hydrophobic coating is applied on the metal layer. In another aspect of the invention, the metal layer may be roughened to better adhere to a coating such as an oleophobic or hydrophobic coating.

[0033] In certain aspects of the invention, the metal layer of the injector web is roughened to include peaks and valleys, and one or more coating layers cover the peaks and valleys of the metal layer to provide a smooth surface.

[0034] In various aspects of the invention, at least one coating is applied within a plurality of pores of an injector mesh, such as a polymeric mesh.

[0035] In another aspect of the present invention, the droplet delivery device including the ejector includes a substrate with a hole, an actuator configured to vibrate the substrate (such as a powered piezoelectric actuator), a liquid supply of the substrate, and one or more coatings applied to the roughened surface of the substrate with a hole. In one aspect, the substrate is a polymer. In one aspect, the one or more coatings of the substrate include an oleophobic coating. In another aspect, the one or more coatings of the substrate include a deposited metal. In another aspect, the one or more coatings of the substrate include a hydrophobic coating.

[0036] Although the present invention has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope of the invention. In addition, many modifications may be made to adapt specific circumstances or materials to the teachings without departing from its basic scope. Therefore, the present invention is intended not to be limited to the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A droplet delivery device comprising an ejector, the ejector comprising: a polymer network having pores; as well as A metal layer is deposited on the polymer network.

2. The droplet delivery device of claim 1, wherein the hole is formed by laser ablation.

3. The droplet delivery device of claim 1, wherein the metal layer is sputtered onto the polymer mesh.

4. The droplet delivery device of claim 3, wherein the metal layer comprises one or more of gold, palladium, platinum and silver.

5. The droplet delivery device of claim 4, wherein the metal layer comprises one or more noble metal alloys.

6. The droplet delivery device of claim 2, wherein the metal layer comprises one or more of gold, palladium, platinum and silver.

7. The droplet delivery device of claim 1, wherein the metal layer comprises one or more of gold, palladium, platinum, and silver.

8. The droplet delivery device of claim 7, wherein the polymer network comprises one or more of polymethyl methacrylate, polyetheretherketone, polyetherimide, polyvinylidene fluoride, ultra-high molecular weight polyethylene, polysulfone, polyimide, fluorinated ethylene propylene, perfluoroalkoxyalkane, and polytetrafluoroethylene.

9. The droplet delivery device of claim 1, wherein the polymer network is nanomolded.

10. The droplet delivery device of claim 1, further comprising an oleophobic or hydrophobic coating on the metal layer.

11. The droplet delivery device of claim 1, further comprising a hydrophobic coating on the metal layer.

12. The droplet delivery device of claim 11, wherein the metal layer is roughened.

13. The droplet delivery device of claim 10, wherein the metal layer is roughened.

14. The droplet delivery device of claim 1, wherein the metal layer is roughened to include peaks and valleys, and the one or more coating layers cover the peaks and valleys of the metal layer to provide a smooth surface.

15. The droplet delivery device of claim 15, further comprising at least one coating applied within the plurality of pores of the polymer network.

16. A droplet delivery device comprising an ejector, comprising a substrate having pores; an actuator configured to vibrate the substrate; a liquid supply to the substrate; as well as One or more coatings are applied to the roughened surface of the substrate.

17. The droplet delivery device of claim 16, wherein the substrate is a polymer.

18. The droplet delivery device of claim 16, wherein the one or more coatings comprise an oleophobic coating.

19. The droplet delivery device of claim 16, wherein the one or more coatings comprise a deposited metal.

20. The droplet delivery device of claim 16, wherein the one or more coatings comprise a hydrophobic coating.