Nebulizer Reservoir Ribs Prevent Air Bubble Formation
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Solution Overview
Problem
Existing aerosol generators, particularly those using vibrating mesh technology, face issues with air bubble formation near the liquid reservoir outlet due to trapped air, which can lead to aerosolization cessation and are complex to address with separate outlet chambers.
Innovation Solution
Incorporating elongate ribs with vertices on the reservoir wall near the outlet to prevent bubble formation by directing air escape and ensuring efficient liquid delivery to the aperture plate, reducing the likelihood of airlock and maintaining consistent aerosolization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a narrow geometry reservoir outlet is used to control liquid flow, then liquid delivery precision is improved, but air bubble formation increases
Solution Approach 1:
A hydrophobic barrier layer is introduced as an intermediary between the reservoir outlet and the aperture plate. This layer acts as a mediator that allows liquid to pass through while blocking air bubbles, thus maintaining precise liquid delivery without the harmful effect of air bubble formation at the narrow outlet.
Solution Approach 2:
The liquid is encouraged to rush through the hydrophobic barrier layer quickly, skipping over potential air bubble formation zones. The rapid liquid flow through the barrier prevents air from becoming trapped and blocking the outlet, maintaining continuous liquid delivery.
2Object-affected harmful factors
If a separate outlet chamber for bubbles is provided, then air bubble removal is improved, but device complexity increases
Solution Approach 1:
The air bubble removal function is extracted from the main reservoir structure and integrated into the hydrophobic barrier layer itself. Instead of adding a separate outlet chamber, the barrier layer is designed to inherently repel and remove air bubbles through its hydrophobic properties, simplifying the overall device structure.
Solution Approach 2:
The hydrophobic barrier layer performs multiple functions simultaneously: it controls liquid flow, blocks air bubbles, and facilitates air bubble removal. This multi-functional element eliminates the need for separate bubble removal chambers, reducing device complexity while maintaining effective air bubble management.
3Productivity
If the membrane pumps liquid continuously, then liquid delivery efficiency is improved, but air back-pumping into the reservoir increases
Solution Approach 1:
The hydrophobic barrier layer serves as a mediator that allows liquid to pass through in continuous pump operation while blocking air from being pumped back into the reservoir. This maintains high liquid delivery efficiency while preventing air contamination.
4Reliability
If O-rings are used to seal the piezo element, then sealing effectiveness is improved, but liquid reservoir exit geometry is constrained
Solution Approach 1:
The hydrophobic barrier layer acts as an intermediary sealing mechanism that does not require O-rings. This allows greater flexibility in designing the liquid reservoir exit geometry while maintaining effective sealing and preventing air bubble formation.
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
The solution effectively prevents air bubble formation, ensuring continuous aerosolization and simplifying the design by eliminating the need for multiple chambers, thus enhancing the reliability and efficiency of aerosol generation.
Implementation Method 1
The membrane (10) is driven by an annular piezo element (11)... vibrated at a frequency of typically 127 to 157 kHz
Implementation Method 2
this action breaks the surface tension of the liquid on the aperture plate and creates an aerosol plume
Implementation Method 3
a hydrophobic barrier layer in the form of a hydrophobic coating or membrane
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A liquid reservoir (100) of a nebulizer has a funnel portion (102) with ribs (103, 104) extending downwardly along a side wall towards a reservoir outlet (105). The ribs (103, 104) prevent the formation of air bubbles between the aperture plate and medication as any trapped air will be expelled along the geometry formed by the rib or groove and reservoir wall. Bubble formation is therefore prevented with only modification of the wall internal surface configuration of the reservoir.