Multi-Surface Acoustic Nebuliser With Edge-Fed Liquid Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current SAW nebulisation platforms face issues such as cumbersome fluid chip interfacing, weak flow rates, spurious ejection of large droplets, and low nebulisation rates, limiting their practical and commercial use, particularly in pulmonary drug delivery applications.
Innovation Solution
A nebuliser design utilizing a piezoelectric substrate with a liquid supply system that includes a reservoir and a rigid supply conduit, supported by a displaceable mount, and using hybrid acoustic waves (SAW and SRBW) to nebulise liquid from both transducer and non-transducer surfaces, with droplet size control via baffles and adjustable substrate spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a wick is placed on the transducer surface to supply liquid, then liquid supply is achieved, but SAW damping increases and heating occurs
Solution Approach 1:
The liquid supply function is extracted from the transducer surface by using a separate wick that contacts only the peripheral edge of the piezoelectric substrate. This separates the liquid supply pathway from the SAW propagation path, eliminating the damping effect while maintaining liquid supply capability.
Solution Approach 2:
A wick acts as an intermediary element that transfers liquid from the reservoir to the substrate edge without directly contacting the transducer surface. The wick mediates between the liquid reservoir and the acoustic field, enabling liquid supply while protecting the SAW from damping.
2Quantity of substance
If a wick contacts the transducer surface, then liquid can be supplied, but spurious large droplets are produced
Solution Approach 1:
The liquid supply contact point is extracted from the active transducer surface and relocated to the peripheral edge. This spatial separation ensures that liquid is supplied away from the SAW interaction zone, preventing the formation of spurious large droplets while maintaining efficient liquid delivery.
3Productivity
If SAW is used to nebulise liquid, then nebulisation occurs, but flow rates are weak
Solution Approach 1:
The invention utilizes both surfaces of the piezoelectric substrate for liquid supply and nebulisation. By contacting liquid to both the front and back surfaces of the substrate, the effective nebulisation area is doubled, significantly increasing the overall nebulisation rate and productivity.
4Reliability
If the device is custom-made for laboratory applications, then performance is optimized for specific uses, but ease of operation decreases
Solution Approach 1:
The nebuliser design incorporates universal features including a standardized reservoir interface, simple wick-based liquid supply, and adjustable baffle positions that can accommodate different liquid viscosities and application requirements. This multi-functionality enables the device to serve both laboratory and commercial applications while remaining easy to operate.
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 design achieves higher nebulisation rates (up to 10.0 ml/min) and controlled droplet sizes (0.1 μm to 100 μm), reducing undesirable heating and improving reliability and efficiency for therapeutic and non-therapeutic applications.
Implementation Method 1
at least one piezoelectric substrate accommodated within the housing and having a transducer surface upon which is located at least one electroacoustic transducer for generating acoustic wave energy within the substrate
Implementation Method 2
at least one piezoelectric substrate accommodated within the housing and having a transducer surface upon which is located at least one electroacoustic transducer
Implementation Method 3
using hybrid acoustic waves (SAW and SRBW) to nebulise liquid
Implementation Method 4
The use of surface acoustic waves (SAW) for the nebulisation of liquids has been proposed since the 1990's
Data Source
AI summary
A nebuliser for nebulising liquid droplets includes a housing; at least one piezoelectric substrate accommodated within the housing and having a transducer surface upon which is located at least one electroacoustic transducer for generating acoustic wave energy within the substrate, and an opposing non-transducer surface; and a liquid supply system for supplying a liquid to at least one of the transducer and non-transducer surfaces. The liquid supply system includes a reservoir for accommodating the liquid, and at least one relatively rigid supply conduit in contact with the substrate for supplying the liquid from the reservoir to the substrate.