Microvalve Spray Nozzle for Preservative-Free Microbial Sealing
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Solution Overview
Problem
Existing spray devices fail to guarantee complete microbial closure, allowing contamination of preservative-free fluids due to manufacturing tolerances and residual fluid communication with the environment, especially in pharmaceutical applications.
Innovation Solution
A spray device with a nozzle body incorporating a microbial barrier and microvalve means that opens at a predetermined pressure threshold, ensuring a normally-closed state to prevent microbial contamination, featuring precise manufacturing through semiconductor technology and micromachining for accurate membrane and cavity control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a known exit valve is used in the spray device, then the valve can contribute to safeguarding microbial integrity and preventing dripping, but complete mechanical closure to prevent microbial passage cannot be guaranteed due to manufacturing tolerances
Solution Approach 1:
The invention extracts and eliminates the problematic known exit valve from the system. Instead of relying on a mechanical valve that cannot guarantee complete closure due to manufacturing tolerances, the patent removes this component entirely and replaces it with a valveless nozzle design that achieves microbial integrity through alternative means such as sterile filtration and controlled fluid dynamics.
Solution Approach 2:
The invention replaces the mechanical valve system with a non-mechanical approach. Rather than using a valve that requires precise mechanical closure, the patent employs fluid dynamic control, sterile filtration systems, and nozzle design that prevent microbial passage without relying on mechanical sealing, thereby substituting a mechanical system with a more reliable non-mechanical solution.
2Object-affected harmful factors
If antimicrobial coating is applied to spray device surfaces, then microbial contamination is inhibited, but the coating may wear off or degrade over time reducing effectiveness
Solution Approach 1:
The invention adopts a disposable nozzle design where the nozzle is replaced after a single use or after a limited number of uses. This eliminates the need for durable antimicrobial coatings by ensuring that any potential contamination or coating degradation does not affect subsequent uses, as the nozzle itself is discarded. The low cost of the disposable nozzle makes this approach economically viable.
Solution Approach 2:
The invention segments the spray device into replaceable components, with the nozzle being a separate disposable unit. This segmentation allows the critical fluid-contact surface to be replaced rather than maintained, eliminating the need for long-lasting antimicrobial coatings on permanent components.
3Object-affected harmful factors
If a separate pre-filter body is added upstream of the spray nozzle, then microbial filtration is improved, but the device complexity and material involved substantially double
Solution Approach 1:
The invention merges the filtration function directly into the nozzle structure itself. Rather than adding a separate pre-filter body upstream of the nozzle, the patent integrates sterile filtration capabilities within the nozzle design, combining multiple functions (fluid delivery, spray generation, and filtration) into a single integrated component. This reduces device complexity while maintaining microbial protection.
Solution Approach 2:
The invention makes the nozzle multi-functional by integrating filtration, fluid delivery, and spray generation capabilities into a single component. The nozzle serves not only as the spray outlet but also incorporates sterile filtration, eliminating the need for separate filtration components and reducing overall device complexity.
4Object-affected harmful factors
If the spray nozzle cavity volume is reduced to minimize residual fluid, then microbial contamination risk is lowered, but the device may require higher pressure to deliver adequate spray volume
Solution Approach 1:
The invention optimizes the nozzle cavity volume to a specific parameter range that balances microbial contamination prevention with adequate spray delivery. By carefully selecting and controlling the cavity volume parameter, the design achieves minimal residual fluid while maintaining sufficient fluid reservoir for complete spray delivery at standard operating pressures, eliminating the need for excessive pressure.
Solution Approach 2:
The invention employs dynamic fluid delivery that adapts to the cavity volume. The nozzle design incorporates fluid dynamic features that ensure complete evacuation of the reduced-volume cavity, using pressure pulses or flow modulation to deliver the entire fluid charge even from a minimal cavity volume, thereby preventing residual fluid contamination without requiring continuously high pressure.
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 device effectively seals the fluid delivery system, reducing microbial immigration and maintaining fluid integrity by minimizing the volume of fluid exposed to contamination, suitable for preservative-free and pharmaceutical applications.
Implementation Method 1
micro-valve means that open once a predetermined upstream pressure threshold is exceeded and are in a normally-closed state in a non-pressurized state
Implementation Method 2
at least one spray nozzle having a nozzle membrane with at least one nozzle orifice for releasing a microjet spray of said fluid
Implementation Method 3
A microjet is here defined as a single or a multiple number of jets operating in the Rayleigh breakup regime
Data Source
Figure 1~4
Figure 5~6
Figure 7~8
AI summary
The present invention relates to a spray device, comprising a spray nozzle body (2) and a substantially planar membrane layer (6) suspended over a nozzle cavity (3) to generate microjets, especially for pharmaceutical applications, in particular preservative free formulations. The nozzle body (2,8) contains a microbial barrier, particularly a microvalve (23,24) between a fluid supply channel (9) and said cavity (3).