Multi-Reflection Optical Cavity for UV Sterilization Photon Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing UV technologies for deactivating infectious particles, such as the SARS-CoV-2 virus, are limited by high costs and long exposure times due to inefficient use of UV photons, with prior art devices achieving only a small probability of interaction between UV photons and sample materials.
Innovation Solution
A method and apparatus utilizing a reaction chamber with multiple reflective surfaces, including concave mirrors and dielectric mirrors with high reflectivity, to increase the optical path length of electromagnetic radiation, thereby enhancing the probability of interaction between UV radiation and reactant materials through multiple reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If UV source is positioned proximate to sample material with simple arrangement, then device complexity is reduced, but probability of photon interaction with sample material is small
Solution Approach 1:
The patent transitions from a simple linear UV source-sample arrangement to a multi-dimensional optical cavity system with reflective surfaces arranged to create multiple reflection paths. The optical cavity extends the interaction volume and allows photons to traverse the sample region multiple times through controlled reflections, dramatically increasing interaction probability without proportionally increasing device complexity.
Solution Approach 2:
The patent introduces reflective surfaces (mirrors) as intermediary elements between the UV source and sample material. These intermediaries redirect and confine photons within the optical cavity, ensuring multiple passes through the sample region. The reflective surfaces act as mediators that enhance photon-sample interaction without requiring direct line-of-sight proximity between source and sample.
2Productivity
If metallic walls with specular reflection are used, then some photon flux is reflected multiple times, but theoretical amplification is limited to 10-fold due to 90% reflectivity
Solution Approach 1:
The patent changes the key parameter of reflectivity by transitioning from metallic mirrors (90% reflectivity) to dielectric mirrors (99% reflectivity). This parameter change in the reflective surfaces' optical properties reduces energy loss per reflection from 10% to 1%, enabling significantly higher photon flux amplification (up to 100-fold theoretical limit) while maintaining the same optical cavity geometry.
3Loss of energy
If diffuse reflector such as sintered PTFE is used, then reflectivity increases to 97%, but effective amplification is less due to short mean free photon path length
Solution Approach 1:
The patent employs specular (mirror-like) reflection instead of diffuse reflection to maintain collimated photon paths. This allows photons to travel longer distances between reflections and maintains a more predictable, extended optical path length through the sample region, rather than the randomized short paths created by diffuse reflectors.
4Reliability
If long exposure times are used for UV sterilization, then virus particles can be deactivated, but time required for treatment is excessive
Solution Approach 1:
The patent creates a continuous photon circulation system within the optical cavity where UV photons repeatedly interact with virus particles over an extended period. The reflective surfaces trap photons in continuous circulation, ensuring that each photon has multiple opportunities to interact with viral targets, thereby achieving complete deactivation within a short overall exposure time rather than requiring long single-pass exposure.
5Productivity
If high flux UV radiation is used to reduce exposure time, then sterilization speed increases, but energy cost and operational expense increase
Solution Approach 1:
The patent changes the system's energy efficiency parameter by introducing high-reflectivity dielectric mirrors that reduce photon loss. This allows the system to achieve the same sterilization effect with lower input UV flux, as each photon is utilized more efficiently through multiple reflections. The energy cost is reduced while maintaining sterilization speed because the optical cavity amplifies the effective photon density without requiring proportionally higher source power.
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 approach significantly reduces the required flux and time for UV sterilization, achieving efficient energy use and cost-effective UV sterilization, enabling real-time sterilization of air and surfaces with enhanced UV photon interaction.
Implementation Method 1
a dielectric mirror with reflectivity at the selected wavelengths greater than 99%
Implementation Method 2
dielectric mirror formed by plurality of layers of dielectric materials arranged in a stack
Implementation Method 3
at least one of the reflective surfaces is a concave mirror
Implementation Method 4
concave mirror...arranged to cause reflections of the electromagnetic radiation back and forth within a volume
Implementation Method 5
increasing the probability of the electromagnetic radiation interacting with the reactive materials
Data Source
AI summary
A flow through photochemistry apparatus and methods of use are disclosed in the present application. One or more reactant materials are passed through a reaction chamber and are exposed to electromagnetic radiation. The reaction chamber has reflective walls arranged to reflect electromagnetic radiation across the volume of the chamber a plurality of times, thereby increasing the probability of the electromagnetic radiation interacting with the reactive materials. The reaction chamber may be used for sterilization and photochemistry applications.