Photodefined Aperture Plate for Sub-10 μm Aerosol Control
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Solution Overview
Problem
Existing electroforming processes for manufacturing aperture plates in liquid nebulizers struggle with high manufacturing variability, low yield, and difficulty in controlling aperture size and shape, particularly for sizes below 10 μm, which affects the efficiency and consistency of aerosol delivery to the pulmonary system.
Innovation Solution
A photolithography-based method is employed to manufacture aperture plates, involving multiple photolithography masks and etching steps to precisely define aperture size, shape, and distribution, decoupling flow rate from droplet size, and enabling scalable production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If electroforming process is used to manufacture aperture plates, then manufacturing capability is achieved, but manufacturing precision and aperture size control are poor
Solution Approach 1:
The patent replaces the electroforming process (electrochemical deposition) with a photolithography-based fabrication process. This involves depositing a metal layer on a substrate, patterning it through photolithography to define aperture positions, and selectively removing material to create precise apertures. This substitution enables superior control over aperture size, shape, and distribution, achieving manufacturing precision that electroforming cannot provide for sub-10 μm apertures.
Solution Approach 2:
The patent employs photolithography masks with precisely controlled parameters to define aperture characteristics. By changing the mask patterns, aperture sizes, shapes, and distributions can be precisely controlled independently. This parameter control approach allows for consistent reproduction of aperture geometries with tight tolerances, directly improving manufacturing precision while maintaining ease of manufacture through standard semiconductor fabrication techniques.
2Manufacturing precision
If aperture size is reduced below 10 μm for better pulmonary delivery, then droplet size is improved, but manufacturing variability increases
Solution Approach 1:
The patent replaces electroforming with photolithography-based fabrication, which maintains consistent precision across different aperture sizes. This substitution eliminates the manufacturing variability that typically increases when aperture size is reduced below 10 μm in electroforming processes. The photolithography approach provides reliable control over sub-10 μm apertures, improving both manufacturing precision and yield consistency.
Solution Approach 2:
The patent uses photolithography masks to pre-define the exact aperture pattern before material removal. This preliminary patterning step ensures that aperture positions, sizes, and shapes are precisely determined before fabrication continues, reducing variability. The mask serves as a template that guides subsequent processing steps, ensuring consistent results even for small sub-10 μm apertures.
3Manufacturing precision
If multiple aperture parameters are controlled simultaneously, then aerosol delivery precision is improved, but device complexity increases
Solution Approach 1:
The patent segments the aperture plate into multiple layers or levels, with each layer containing apertures of specific sizes and patterns. This segmentation allows different aperture parameters (size, shape, distribution) to be controlled independently in different layers. The layered structure enables precise control over droplet size and flow characteristics without requiring complex single-layer designs, thereby improving aerosol delivery precision while managing manufacturing complexity through modular fabrication.
Solution Approach 2:
The patent extends the aperture design from a two-dimensional plane to three-dimensional structures by varying aperture depth, shape, and arrangement across multiple levels. This dimensional expansion allows independent control of multiple parameters (aperture size, depth, distribution) without proportionally increasing manufacturing complexity. The 3D structure enables sophisticated aerosol delivery control through geometric variations that can be fabricated using standard photolithography and etching processes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for precise control of aperture size and shape, increasing manufacturing yield and reducing costs, while enabling independent control of flow rate and droplet size distribution, enhancing the efficiency of aerosol delivery to the pulmonary system.
Implementation Method 1
A photolithography-based method is employed to manufacture aperture plates, involving multiple photolithography masks and etching steps to precisely define aperture size, shape, and distribution
Implementation Method 2
electroplating a first material above the exposed portions of the releasable seed layer and defined by the first mask
Data Source
AI summary
In one embodiment, a method for manufacturing an aperture plate includes depositing a releasable seed layer above a substrate, applying a first patterned photolithography mask above the releasable seed layer, the first patterned photolithography mask having a negative pattern to a desired aperture pattern, electroplating a first material above the exposed portions of the releasable seed layer and defined by the first mask, applying a second photolithography mask above the first material, the second photolithography mask having a negative pattern to a first cavity, electroplating a second material above the exposed portions of the first material and defined by the second mask, removing both masks, and etching the releasable seed layer to release the first material and the second material. The first and second material form an aperture plate for use in aerosolizing a liquid. Other aperture plates and methods of producing aperture plates are described according to other embodiments.