United States Patent 7,896,264: Scope, Claims, Expiration, and Microstructured Nozzle Patent Landscape

U.S. Patent 7,896,264 covers a silicon microstructured nozzle that combines a zigzag, multi-row particle filter with a downstream collecting chamber containing pillar-shaped flow elements. Its central inventive concept is to improve liquid distribution and mechanical stability without materially increasing downstream flow resistance. The patent also covers inhalation atomizers using the nozzle and a wafer-level manufacturing process.

The patent is a device and manufacturing patent, not a drug-composition patent. It does not create Orange Book-listed exclusivity, new-drug exclusivity, biosimilar exclusivity, or a Paragraph IV pathway. Based on its early-2000s priority and filing chronology, the U.S. patent term ended in 2024, subject to any recorded patent-term adjustment or terminal disclaimer.

What does U.S. Patent 7,896,264 protect?

The patent protects a microstructured nozzle with four required functional zones:

An inlet for unfiltered liquid.
A main filter between the inlet and outlet.
A zigzag arrangement of transverse projections forming liquid channels.
A downstream filtrate collecting chamber containing pillar-shaped built-in elements.

The key limitation is hydraulic. The cross-sectional area available through the pillar field must be greater than the effective cross-sectional area of the main-filter channels. The pillar elements therefore must not substantially increase flow resistance.

Claim 1 is the broadest apparatus claim. It requires the combination of:

Claim element	Scope
Inlet	Receives unfiltered fluid
Outlet	Discharges filtered fluid and defines the flow direction
Main filter	Contains multiple zigzag projections extending transversely from a base plate
Channels	Formed between the projections
Spikes	Projections extend toward both inlet and outlet directions
Collecting chamber	Located between the main filter and outlet
Built-in elements	Pillar-shaped elements extending transversely from the base plate
Spatial arrangement	Elements cover the outlet region and at least part of the space between outlet-directed spikes
Hydraulic relationship	Effective open area around the pillars exceeds the effective area of the main-filter channels

A device that has only a microfilter, only a zigzag channel structure, or only downstream posts would not meet the full combination of claim 1.

How strong is claim 1 of U.S. Patent 7,896,264?

Claim 1 is technically narrow because it requires several structural and functional limitations in combination. Its strongest limitation is the relationship between the pillar-field flow area and the main-filter flow area.

The claim does not merely require pillars downstream of a filter. It requires that the pillars be dimensioned and spaced so they do not substantially increase flow resistance. This creates a potential claim-construction issue because "do not substantially increase" is a relative performance limitation. In an enforcement dispute, the patent owner would likely need to establish:

The effective flow area of the main-filter channels.
The effective flow area through the pillar region.
The test conditions used to determine flow resistance.
Whether the pillar arrangement materially changes pressure drop.
Whether the accused device has the claimed inlet-to-outlet flow architecture.

The claim is stronger against products that reproduce the entire architecture, particularly silicon or glass microfluidic nozzles with the same downstream support grid. It is weaker against:

Filters without pillar-shaped downstream elements.
Devices using a separate support structure outside the fluid path.
Devices with a different filter geometry.
Devices in which the support field creates a measurable and intentionally higher pressure drop.
Products using a membrane, mesh, laser-drilled plate, or porous structure instead of zigzag projections.

The claim does not require an inhalation application. The nozzle may be used in other liquid atomization or microfluidic applications unless another limitation narrows the asserted claim.

Which claims cover the nozzle structure, atomizer, and manufacturing process?

The claims fall into four groups.

Claims 1 through 33: nozzle architecture

Claims 1 through 33 depend on the core microstructured nozzle. They add geometric, dimensional, material, and fabrication limitations.

Important dependent-claim categories include:

Claims	Subject matter
2, 5, 6	Cylindrical, concave, or convex pillar walls
3, 4	Pillar spacing and diameter of 0.005 mm to 0.02 mm
7	Pillars extending from base plate to cover plate
8-12	Position of elements relative to the zigzag center line and spikes
13, 16, 26-28	Base-plate and cover-plate spacing, including constant or tapered spacing
14	Detailed round-column, multi-row filter architecture
15	Projections and built-in elements formed on the base plate
17, 18	Inter-row chambers and oblong collecting chambers
19	Straight, curved, or columnar projections
20-24	Channel height, width, length, cross-sectional shape, and row spacing
25	Zigzag angle of 2° to 25°
29	Wet or dry etching, including anisotropic dry etching
30	Silicon base plate and glass cover plate joined by anodic bonding
31	Conically tapering collecting chamber and outlet nozzle
32	Silicon base and silicon cover joined by direct bonding
33	Repetition of the effective-area relationship in claim 1

Claims 30 and 32 are particularly relevant to semiconductor-style manufacturing. They limit the claimed structure to bonded silicon/glass or silicon/silicon assemblies, depending on the claim.

Claim 34: inhalation atomizer

Claim 34 covers an atomizer for inhalation therapy that includes the microstructured filter of claim 1.

This claim creates a device-level bridge between the nozzle and respiratory products. It does not claim a drug, active ingredient, formulation, dose, treatment method, or patient population. A respiratory product could therefore require separate analysis of:

The active pharmaceutical ingredient.
The formulation.
The container.
The pump or pressure source.
The dose-metering system.
The inhaler housing.
Any separate method-of-treatment patents.

Claim 35: wafer-level manufacturing process

Claim 35 covers a process with the following sequence:

Etching filter projections, built-in elements, inlet, and outlet into one side of a silicon wafer.
Attaching a glass plate to the etched wafer side.
Placing the silicon wafer on an adhesive film.
Separating individual nozzles from the wafer-and-glass assembly with a diamond saw, starting from the glass side.

This claim is narrower than a general process claim because it requires both the wafer-level assembly and the specified singulation sequence.

Claims 36 and 37: pillar geometry and density

Claim 36 covers built-in elements forming equilateral hexagonal designs, with one element at the center and adjacent elements forming the vertices.

Claim 37 requires a density of 200,000 to 300,000 built-in elements per square centimeter. This is a highly specific limitation and may be useful for distinguishing commercial devices with a lower or higher pillar density.

What technical features are most important for infringement analysis?

The following features are likely to control an infringement comparison:

Technical issue	Why it matters
Zigzag projection layout	Separates the claimed filter from straight channels or random posts
Inlet- and outlet-facing spikes	Required by claim 1
Downstream pillar field	Required by claim 1 and central to the patent
Pillar spacing and diameter	Narrowed by claims 3 and 4
Effective open-area relationship	Core functional limitation
Base plate and cover plate	Relevant to claims 7, 13, 16, 26-32
Channel dimensions	Relevant to claims 20-24
Silicon fabrication	Relevant to claims 29, 30, 32, and 35
Pillar density	Relevant to claim 37
Inhalation use	Relevant to claim 34, but not to the broader nozzle claims

A competitor can reduce exposure by altering more than one of these variables. Replacing the zigzag projection filter with a porous membrane, relocating the support pillars outside the collecting chamber, or using a different downstream flow-distribution geometry may avoid the literal scope of claim 1.

The doctrine of equivalents could create residual risk where a product uses a geometrically different structure that performs substantially the same filtering and low-resistance support function in substantially the same way. The degree of risk would depend on prosecution history and any narrowing amendments made during examination.

When did U.S. Patent 7,896,264 lose exclusivity?

U.S. Patent 7,896,264 is an early-2000s patent and its ordinary 20-year patent term ended in 2024. The patent is therefore not a current blocking patent in the United States unless the public patent record shows an unusual patent-term adjustment, patent-term extension, or other enforceable right.

Event	Timing
Earliest claimed priority	Early 2000s
U.S. patent application	Mid-2000s
U.S. publication	Mid-2000s
U.S. grant	2011
Expected ordinary patent-term end	2024
Current status for ordinary patent term	Expired

The grant date does not determine expiration. For a utility patent filed through the international or national-stage system, the term generally runs 20 years from the applicable earliest nonprovisional filing date, subject to adjustment under 35 U.S.C. §§ 154 and 156.[1]

What is the Orange Book status of U.S. Patent 7,896,264?

U.S. Patent 7,896,264 is not an Orange Book drug patent.

The patent covers:

A microstructured nozzle.
A filter architecture.
An inhalation atomizer.
A silicon-wafer manufacturing process.

It does not claim:

A new chemical entity.
A drug substance.
A drug product formulation.
A dosage regimen.
A method of treating a disease with a listed drug.

The FDA Orange Book generally lists patents submitted for approved drug products, including drug substance, drug product, and certain method-of-use patents.[2] A stand-alone nozzle patent would not ordinarily support a Paragraph IV certification unless it were properly submitted and listed against a specific approved drug product.

Does the patent create Paragraph IV or biosimilar risk?

No direct Paragraph IV or biosimilar risk arises from this patent.

Paragraph IV

Paragraph IV litigation applies to an Abbreviated New Drug Application that challenges an Orange Book-listed patent. Because this patent is a device patent and expired in 2024, it does not create a current standalone Paragraph IV barrier.

A generic inhalation product could still face separate issues involving:

Drug formulation patents.
Device patents with later expiration dates.
Dose-counter patents.
Container-closure patents.
Method-of-use patents.
FDA comparative performance requirements.

Biosimilars

The patent has no biosimilar relevance. Biosimilar litigation concerns patents covering biological products, formulations, manufacturing processes, and therapeutic uses under the Biologics Price Competition and Innovation Act. A microstructured nozzle patent is not a biologic-product patent.[3]

What formulations are protected by U.S. Patent 7,896,264?

No drug formulation is protected by the claims provided.

The patent does not specify:

An active ingredient.
Excipients.
Solvent composition.
Particle-size distribution of a drug.
Preservatives.
Osmolality.
Concentration.
Dose.
Therapeutic indication.

Its relevance to a formulation is indirect. A formulation may be delivered through an infringing nozzle, but the formulation itself would not fall within claims 1 through 33, 36, or 37 unless it is part of a separately claimed combination.

Claim 34 covers an inhalation atomizer that includes the claimed microstructured filter. It does not, on its face, require a particular inhalation formulation.

What manufacturing and intellectual-property barriers does the patent cover?

The patent targets semiconductor-style fabrication of high-density liquid-flow structures. The manufacturing limitations include:

Etching microstructures into silicon.
Forming projections and pillar elements on a common base plate.
Bonding a cover plate to the structured surface.
Producing many nozzles from a wafer.
Singulating the nozzles with a diamond saw.
Using anodic bonding for silicon-to-glass assemblies.
Using direct bonding for silicon-to-silicon assemblies.

These limitations could have been commercially important even where a competitor designed around claim 1. Manufacturing know-how may reside in:

Etch depth control.
Sidewall profile control.
Uniformity across the wafer.
Bond integrity.
Clogging resistance.
Pillar collapse prevention.
Nozzle singulation yield.
Pressure-drop control.
Cleaning and inspection procedures.

The patent, however, does not by itself establish ownership of every process used to manufacture silicon micro-nozzles. Separate patents may cover wafer bonding, etching chemistry, nozzle arrays, pump systems, or aerosol performance.

Which companies are challenging or licensing this patent?

The patent does not create a conventional drug-patent challenge market. No Paragraph IV challenger, biosimilar applicant, or drug-patent settlement is implicated by the claims.

The commercially relevant parties are likely to fall into three groups:

Party type	Potential position
Original patent owner or affiliated manufacturer	Uses or licenses the nozzle and atomizer architecture
Respiratory-device manufacturers	May use comparable microstructured nozzle technology
Generic or competing inhaler companies	May design around the expired patent or rely on independent technology

A public patent record for this type of device patent may identify assignments, continuations, divisionals, foreign counterparts, and related applications. Those records should be distinguished from licensing agreements. Patent ownership does not prove that a commercial license exists.

No settlement agreement or public Paragraph IV resolution can be inferred from the claims themselves.

How does this patent compare with competing inhalation-device patents?

U.S. Patent 7,896,264 occupies a narrower technical position than broad inhaler-system patents.

Patent category	Typical protected subject matter	Relationship to U.S. 7,896,264
Drug-substance patent	Active pharmaceutical ingredient	Separate
Formulation patent	Composition and excipients	Separate
Metering patent	Dose measurement or pump delivery	Separate
Inhaler housing patent	Mechanical arrangement and user interface	Separate
Aerosol-generation patent	Atomization mechanism	Potentially overlapping at system level
Micro-nozzle patent	Filter and nozzle microstructure	Core subject of 7,896,264
Manufacturing patent	Etching, bonding, wafer processing	Covered in part by claims 29, 30, 32, and 35

The patent is most relevant to products using vibrating-mesh, microstructured, or precision-etched liquid atomization systems. It is less relevant to conventional dry-powder inhalers, pressurized metered-dose inhalers, and nebulizers that do not use the claimed zigzag microfilter and downstream pillar architecture.

What generic launch scenarios exist?

Because the patent term ended in 2024, the principal current issue is design freedom rather than patent-expiration timing.

Scenario 1: Exact architecture

A competitor reproduces the zigzag filter, downstream pillar field, and effective-area relationship. Literal infringement risk would have existed during the patent term, subject to claim construction and validity.

Scenario 2: Similar filter, different support field

A competitor retains a multi-row microfilter but replaces the pillar-shaped built-in elements with ribs, a mesh, or a separate support plate. This could avoid literal infringement, although the doctrine of equivalents would require analysis.

Scenario 3: Different filter technology

A competitor uses a porous membrane, laser-drilled plate, woven mesh, or non-zigzag channel network. This presents lower risk under the supplied claims.

Scenario 4: Licensed or acquired legacy technology

A manufacturer may continue using the architecture under a historical license, but an expired patent no longer requires a license for the expired U.S. claims. Other unexpired family members, foreign patents, know-how, or related patents could still matter.

What is the geographic coverage of the patent family?

U.S. Patent 7,896,264 has geographic effect only in the United States. Foreign counterparts, if granted, must be assessed independently because:

Claim scope may differ.
Examination amendments may differ.
Patent terms may differ.
Some foreign rights may have expired earlier or later.
Validation and renewal requirements vary by jurisdiction.
Enforcement history may not transfer across borders.

A global freedom-to-operate review should examine the patent family in Europe, Germany, Japan, China, and other jurisdictions where microstructured inhalation nozzles are manufactured or sold. The U.S. expiration date does not establish freedom to operate in those markets.

What patent litigation affects U.S. Patent 7,896,264?

The supplied claims do not identify an active U.S. infringement action, claim-construction ruling, inter partes review, or Paragraph IV case. Because the patent is expired, a new U.S. enforcement action seeking prospective exclusion would generally be unavailable for ordinary future activity, although historical damages issues can depend on filing dates, notice, estoppel, and limitation periods.

The most important litigation questions would have been:

Whether "effective cross-sectional area" is definite.
Whether "do not substantially increase a flow resistance" is definite and measurable.
Whether the accused structure has a true collecting chamber.
Whether the pillars cover the required outlet and spike regions.
Whether the accused device contains the claimed zigzag projections.
Whether prosecution history narrowed the meaning of "pillar-shaped."
Whether claim 35 requires the exact stated manufacturing sequence.

Key Takeaways

U.S. Patent 7,896,264 protects a microstructured liquid nozzle, not a drug or formulation.
Claim 1 requires a zigzag projection filter plus a downstream pillar-containing collecting chamber.
The effective-open-area limitation is central to both scope and infringement analysis.
Claims 29, 30, 32, and 35 target silicon etching, bonding, wafer processing, and singulation.
Claim 34 extends the technology to inhalation atomizers.
Claim 37 narrows the invention to a pillar density of 200,000 to 300,000 elements per square centimeter.
The patent’s ordinary U.S. term ended in 2024.
It is not an Orange Book drug patent and does not create standalone Paragraph IV or biosimilar risk.
Current commercial risk is more likely to arise from related, later-expiring device, formulation, manufacturing, or foreign patents.
Expiration of this patent does not eliminate independent trade-secret, regulatory, product-liability, or third-party patent risks.

Frequently Asked Questions

Can a generic inhaler use the nozzle design after 2024?

Yes, the expired U.S. claims no longer provide ordinary prospective patent exclusivity. Related unexpired patents and foreign rights must be reviewed separately.

Does claim 34 cover a specific respiratory drug?

No. Claim 34 covers an inhalation atomizer containing the claimed microstructured filter. It does not require a particular active ingredient or formulation.

Is a pillar-supported microfilter automatically covered by claim 1?

No. The device must also have the claimed zigzag projections, inlet and outlet arrangement, collecting chamber, pillar placement, and effective-area relationship.

Does a silicon nozzle necessarily infringe this patent?

No. Silicon is expressly narrowed in claims 30 and 32, but claim 1 is not limited to silicon. A silicon nozzle still must satisfy every limitation of the asserted claim.

Can the expired patent still affect an FDA approval?

Not as an ordinary active U.S. patent barrier. FDA review may still consider device performance, quality, safety, and combination-product requirements, while separate patents may affect commercialization strategy.

References

United States Code. (2024). 35 U.S.C. §§ 154, 156. Patent term and patent term extension provisions.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
United States Code. (2024). 42 U.S.C. § 262. Public Health Service Act provisions governing biological products and biosimilars.
United States Patent and Trademark Office. (2011). U.S. Patent No. 7,896,264, Microstructured nozzle and atomizer.
U.S. Food and Drug Administration. (2024). Orange Book: Approved drug products with therapeutic equivalence evaluations.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Germany	103 30 370	Jun 30, 2003
	03027927	Dec 04, 2003
	03027927	Dec 4, 2003

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	044954	⤷ Start Trial
Austria	485891	⤷ Start Trial
Australia	2004251432	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,896,264

Summary for Patent: 7,896,264