United States Patent 7,896,264 (Microstructured Nozzle): Scope, Claim Architecture, and U.S. Patent Landscape
What is the invention protected by US 7,896,264?
US 7,896,264 claims a microstructured nozzle used as a filtered-fluid flow path, defined by a specific zigzag microfilter plus a filtrate collecting chamber containing pillar-shaped built-in elements arranged so that the chamber’s effective permeability is not materially worse than the permeability created by the filter projections.
The dominant technical problem statement implicit in the independent claim is: adding a post/pillar element field inside the filtrate chamber can increase hydraulic resistance; claim 1 requires an arrangement where the net effective cross-sectional area available for flow in the pillar spacing field is greater than the effective cross-sectional area represented by the filter-projection throughflow channels, so flow resistance is not substantially increased.
What is the core claim 1 structure (independent claim scope)?
Claim 1 element map (functional and structural)
Claim 1 requires all of the following in one microstructured nozzle:
-
Inlet/outlet and flow direction
- An inlet for unfiltered fluid
- An outlet for filtered fluid defining a flow direction
-
Main microfilter between inlet and outlet
- A main filter
- The main filter has a plurality of zigzag projections:
- extend transversely to the flow direction
- extend from a base plate
- The projections:
- define plurality of channels
- form spikes directed toward inlet and outlet directions
-
Filtrate collecting chamber located between the main filter and outlet
- A filtrate collecting chamber sits between:
- the main filter
- and the outlet
- The chamber includes pillar-shaped built-in elements:
- extend from the base plate transversely to flow
- cover an area between the outlet and main filter
- and extend into at least part of an area extending between the zigzag projections directed toward the outlet
-
Critical permeability / flow-resistance condition
- One or more spacings between the built-in elements each form a throughflow channel
- The claim imposes a comparison of effective cross-sectional areas:
- effective cross-sectional area transverse to flow through pillar spacings
is greater than the corresponding effective cross-sectional surface area of throughflow channels formed by the projections of the main filter
- Result: built-in elements do not substantially increase flow resistance
Claim 1 “design freedom” and hard boundaries
Hard boundaries (must-have)
- Zigzag projection geometry as a transverse projection set from a base plate defining channels and inlet/outlet-directed spikes.
- A filtrate collecting chamber that sits between the main filter and outlet.
- Pillar-shaped built-in elements extending from the base plate that occupy the outlet-side region and at least partially extend into the outlet-directed projection area.
- The quantitative effective-permeability inequality is mandatory.
Design flexibility (still within claim 1)
- Built-in elements’ profile is specified by dependent claims (cylindrical/concave/convex). The independent claim only requires “pillar-shaped built-in elements.”
- Chamber cross-section tapering and nozzle-outlet configuration are dependent.
- Fabrication pathway is addressed in process claim 35 (independent device claims still capture structure regardless of manufacturing method).
How dependent claims narrow the scope (claims 2 to 33)?
Below is a structured “scope compression” view: what additional features each dependent claim imposes.
Built-in elements geometry, placement, and density (claims 2 to 7, 10 to 12, 37)
Profile
- Claim 2: built-in elements have a cylindrical circumferential wall
- Claim 5: circumferential wall is concave
- Claim 6: circumferential wall is convex
Axial extent
- Claim 7: built-in elements extend from base plate to a cover plate
Formation modes relative to zigzag
- Claim 10: built-in elements are integral with base plate on outlet side, up to the central line
- Claim 11: built-in elements formed “right into” spikes projecting toward the inlet
- Claim 12: built-in elements formed in front of and behind the zigzag configuration in the flow direction
Spacing and size ranges
- Claim 3: spacing between built-in elements: 0.005 mm to 0.02 mm
- Claim 4: built-in element diameter: 0.005 mm to 0.02 mm
Density
- Claim 37: built-in elements are 200,000 to 300,000 per square centimeter
Projection geometry and zigzag layout (claims 8, 9, 13 to 16, 17 to 24, 25)
Zigzag projection sub-features
- Claim 8: projections define:
- an inlet side of the zigzag configuration between inlet and projections
- an outlet side of zigzag between projections and outlet
- a central line
Coverage
- Claim 9: projections arranged side-by-side over the entire width of the filter
Base/cover plate spacing relationships
- Claim 13: spacing around projections and cover plate within a row:
- is about the same size as channel width on the inlet-side where fluid enters the row
- Claim 16: base plate flat; base-to-cover spacing around projections:
- is between half and twice the channel width at the inlet-side
Row interactions / chamber behavior
- Claim 17: facing sides of adjacent projection rows define a cohesive chamber:
- fluid from all channels flows between a first row’s channels
- then flows out into all channels between projections of next row
Collecting chamber cross-section and feeding/discharge
- Claim 18: collecting chamber has:
- oblong cross section from inlet slot to first row, carrying unfiltered fluid into all channels of first row
- oblong cross section from last row to outlet slot, carrying filtered fluid out
Channel and projection shape variants
- Claim 19: projections are posts straight or curved (in flow direction) or columns
- Claim 20: channels are at least twice the height of the channels at entry side; channel cross-section stays constant
- Claim 21: channels:
- length 5 μm to 50 μm
- height 2.5 to 25 μm
- Claim 22: channels barrel-shaped or trapezoidal in cross-section
- Claim 23: channels are ~square at inlet side and widen toward outlet side
- Claim 24: row spacing:
- twice the inlet-side channel width
Inclined zigzag row angle
- Claim 25: rows inclined toward one another at angle α of 2° to 25°
Base plate / cover plate spacing profile (claims 26 to 28)
- Claim 26: constant spacing between base and cover plate in the relevant regions
- Claim 27: spacing between base and cover plate tapers in the flow direction
- Claim 28: spacing increases from row-end near inlet to row-end near outlet
Projection/base fabrication detail and materials (claims 29 to 32)
- Claim 29: base plate structured by wet or dry etching (isotropic or anisotropic), preferably anisotropic dry etching
- Claim 30: base plate is silicon; cover plate is glass; attached by anodic bonding
- Claim 32: base plate is silicon; cover plate is silicon; attached by direct bonding
Filtrate chamber taper and outlet nozzle integration (claim 31)
- Claim 31: collecting chamber tapers conically in flow direction and has at least one nozzle as outlet
Additional numerical permeability statement (claim 33)
- Claim 33: repeats the claim 1 permeability relationship using the “perpendicular to direction of flow” effective area formulation (substantially the same limitation restated)
What other claimed subject matter exists beyond the microstructured nozzle device?
Atomizer claim (claim 34)
- Claim 34: Atomiser for inhalation therapy comprising a microstructured filter according to claim 1
This claim extends the device into an end-use product category.
Manufacturing process claim (claim 35)
- Claim 35: process for producing a nozzle:
- etch microstructures (filter projections, built-in elements, inlet/outlet) into one side of a silicon wafer for many nozzles
- attach a glass plate firmly to the etched side
- place wafer on adhesive film
- produce individual nozzles from assembly using diamond saw starting from glass plate side
This claim is targeted at a specific wafer stack workflow, including glass attachment and saw singulation.
Hexagonal built-in element pattern (claim 36)
- Claim 36: built-in elements form equilateral hexagonal designs:
- center of each hexagon is a built-in element
- each hexagon angle is formed by adjacent built-in elements
What does the claim set imply for infringement scope?
Strongest infringement posture
A product is most likely to fall within the independent claim 1 when it includes:
- a zigzag projection microfilter with channels and spikes formed from a base plate; plus
- a downstream filtrate collecting chamber that incorporates pillar-shaped elements extending from the base; plus
- a geometry ensuring the pillar spacing effective transverse cross-sectional permeability exceeds the filter-projection channel effective cross-sectional surface area.
The “effective cross-sectional area” inequality is the primary non-intuitive limiter. If an accused design uses pillars but lets the pillars dominate flow resistance, it can be designed around even when pillars are present.
Where design-arounds are most plausible (based on claim language)
- Remove pillar field from the filtrate chamber area between main filter and outlet, or change the pillar arrangement so it no longer “covers an area between outlet and main filter” and does not extend into “at least part of” the projection-directed area toward the outlet.
- Keep a downstream chamber but make it a void space, a different porous structure, or a structure not qualifying as “pillar-shaped built-in elements extending from the base plate.”
- Modify geometry so the inequality in claim 1 fails (pillars reduce effective transverse permeability relative to projection channels), while still maintaining filtration function.
Dependent claims create additional narrower “bolt-on” constraints (spacing range, diameter range, bonding method, silicon/glass materials, channel dimensions). Products matching only claim 1 core features but not the numeric subsets remain covered only under claim 1.
U.S. patent landscape: scope-adjacent technologies and risk vectors
A full, authoritative landscape for this specific US publication requires bibliographic and citation extraction from patent databases. No such bibliographic metadata (publication number, filing date, assignee, examiner/citation list, continuation family) is provided here, and claims-only analysis cannot correctly enumerate:
- same-family continuations,
- interferences,
- reexam/IE delays,
- portfolio breadth by assignee,
- citation-based prior art clusters.
Because those items are necessary to produce a complete and accurate landscape, no additional landscape assertions can be made here.
Key Takeaways
- US 7,896,264 claim 1 protects a microstructured nozzle that combines a zigzag projection main microfilter with a downstream filtrate collecting chamber containing pillar-shaped built-in elements extending from the base plate, where the pillar spacing provides effective transverse permeability greater than the projection-channel effective cross-sectional surface area, preventing substantial flow resistance increases.
- The dependent claims heavily constrain:
- pillar geometry (cylindrical/concave/convex), spacing and diameter (0.005–0.02 mm), density (200,000–300,000/cm²), and placement/integration relative to the zigzag spikes.
- zigzag layout and channel dimensions (length 5–50 μm; height 2.5–25 μm; shapes barrel/trapezoidal; inlet square widening toward outlet).
- fabrication/material stack (silicon base with glass anodic bond; or silicon-on-silicon direct bond) and a specific wafer manufacturing method in process claim 35.
- The strongest differentiator for validity and infringement is the explicit effective-permeability inequality in claim 1, not the mere presence of pillars or microchannels.
FAQs
1. What single limitation most controls claim 1 scope?
The requirement that effective transverse permeability through spacings between pillar built-in elements is greater than the effective cross-sectional surface area of throughflow channels formed by the main filter projections, such that built-in elements do not substantially increase flow resistance.
2. Do the claims require specific pillar count or density?
Not in claim 1. Pillar density is specified in claim 37 (200,000 to 300,000 per square centimeter). Independent protection can exist without matching that range.
3. Are there defined channel dimensions in the claim set?
Yes. Dependent claim 21 specifies channel length 5 μm to 50 μm and height 2.5 to 25 μm, plus other geometry-dependent claims (barrel/trapezoidal, square-to-widening).
4. Does the patent claim only the nozzle device?
No. It also includes an atomizer for inhalation therapy (claim 34) incorporating a microstructured filter meeting claim 1, and a manufacturing process (claim 35).
5. Can a design with a downstream pillar field avoid the patent?
A design can attempt to avoid claim 1 by ensuring the effective permeability comparison in claim 1 is not satisfied or by failing structural placement/coverage requirements for the pillars in the filtrate collecting chamber region.
References
[1] United States Patent 7,896,264, “Microstructured nozzle …” (claims 1-37 as provided in prompt).
