Week 1: An Introduction to Fogging and the Evolution of Anti-Fog Tech

Shreyash P - February 12, 2025 7:30 am

Early Testing and Progress on KnoxFog™

Welcome back to week 2 of my research blog! As I dive deeper into my senior research project, I wanted to share an update on the early testing of KnoxFog™ and the progress made in optimizing this novel anti-fog coating for medical applications. Over the next few few weeks, I will be focusing on preliminary data collection, refining application methods, and conducting controlled experiments to evaluate the coating’s effectiveness.

BLGO POST 2 GOALS: This week’s goal is to inform readers about the history of anti-fog solutions and the theoretical science behind their development.

IMPORTANT: The chemical creation of KnoxFog™ is patented and I have signed a NDA to ensure I do not talk about the physical creation of the solution. However, I will gladly explain the science behind the solution 🙂

Lets start off by understanding the evolution of KnoxFog™

Comparing KnoxFog™, Fog Knox™, and VitreOx™

Over the past 20 years, my research professor and her team has developed many versions:

Version 1: VitreOx™: A predicate device known for its hydrophilic properties, which also prevents fogging by creating a continuous water film. However, unlike KnoxFog™, which integrates nanopore technology to absorb condensate molecules, VitreOx™ relies solely on surface energy manipulation, making it less effective in extreme surgical conditions.
Version 2: FogKnox™: A super-hydrophilic anti-fog solution , focusing on rapid application and temporary clarity enhancement. While effective in the short term, it does not maintain long-lasting fog resistance like KnoxFog™
Version 3: KnoxFog™: A semi-solid hyper-hydrophilic anti-fog coating engineered to create a thin, uniform water film that prevents optical distortion. Designed specifically for medical applications, it provides extended fog-free performance and is optimized for biocompatibility.

To understand the key differences between each solution, we need to explore the concepts of hydrophobicity, hydrophilicity, super-hydrophilicity, and hyper-hydrophilicity. These properties determine how water interacts with a surface, influencing fogging behavior:

Hydrophobic surfaces repel water, causing droplets to bead up and create optical distortion.
Hydrophilic surfaces allow water to spread out more but may still form individual droplets that cause minor distortion.
Super-hydrophilic surfaces create a continuous, transparent water film that reduces fogging.
Hyper-hydrophilic surfaces, KnoxFog™ is hyper-hydropilic and take this further by incorporating nanopores that absorb condensate, ensuring prolonged clarity.

KEY IDEA 1: What stands out about KnoxFog™ is that the solution ins semi-solid, not purely liquid or solid. This allows for the solutions to be easily applied, as it has a viscous consistency, but also dry off fast; this prevents long preparation time and also easy aplications for doctors.

Defining Surface Energy and Its Impact on Fogging

Surface energy is a crucial factor in determining how liquids behave on a surface. It is the excess energy at the surface of a material compared to its bulk, which affects the interaction between the surface and water molecules. High surface energy surfaces attract water, promoting wetting and film formation, while low surface energy surfaces repel water, leading to droplet formation and fogging. KnoxFog™ leverages surface energy engineering to maintain optical clarity under surgical conditions.

KEY IDEA 2: Replicating the surface energy of the proposed anti-fog solution to the surface energy of water will prevent the most distortion.

Comparing KnoxFog™, Fog Knox™, and VitreOx™ Continued…

As I refine KnoxFog™, I’ve also been analyzing its performance in relation to similar technologies, including Fog Knox™ and VitreOx™. Each of these coatings has distinct characteristics:

KnoxFog™: A hyper-hydrophilic anti-fog coating engineered to create a thin, uniform water film that prevents optical distortion. Designed specifically for medical applications, it provides extended fog-free performance

Fig. 1 Phenomenological model showing how the super-hydrophilic (c) and hyper-hydrophilic (d) properties of a surface maximize their surface energy γT. Maximizing the surface energy maximizes the surface’s energy interaction with water. The principle of minimum energy, aka the 2nd Law of Thermodynamics requires that interaction to decrease the surface energy of the water-surface system, thus eliminating water condensation into 3D drops, as in (a, b).

The difference between hyper-hydrophilic and the predicate device, super-hydrophilic is illustrated in Figure 2 as follows.

Fig. 2 explains what ‘Hyper-Hydrophilic’ means 1. Condensing water is partly absorbed by the coating, new from super-hydrophilic, which is a thin solid film, not a liquid. 2. Accumulating water literally ‘crawls’ off the surface towards the edge of the lens, thereby limiting water accumulation and dissolution of the coating.

My Insights: I was not present in the lab during the early creation of VitreOx and early R&D for FogKnox. I was present and contributed a big role in R&D Dev. lead for the KnoxFog Solution. I had to catch up on the history of previous versions by reading previous scientific papers (2016 VitreOx March APS Paper). I enjoyed learning about how surface energy (a topic mentioned in chem) was seen applied in real world scenarios in the lab. I loved connecting physics and chemistry topics in the lab.

Currently, as I work on this blog, my research team is finalizing the animal testing for the anti-fog solution and pursuing FDA clearance. Additionally, I am working on writing the introduction section of my research paper.

Final Thoughts

This journey has been both exciting and challenging, but the potential impact of KnoxFog™ on surgical precision and safety continues to motivate me. In my next blog post, I’ll be discussing the testing of the solution and experimentation. In the future weeks I will dive into development of the casing solution for the anti-fog and other parts of my journey in creating a fog-free future.

Stay tuned, and as always, feel free to share your thoughts and questions!

Comments:

All viewpoints are welcome but profane, threatening, disrespectful, or harassing comments will not be tolerated and are subject to moderation up to, and including, full deletion.

camille_bennett

Hi Shreyash, such cool work! What does it take to get a product cleared by the FDA?

February 18, 2025 at 12:42 pm - Reply

shreyash_p

Dear Ms. Bennett, thank you so much for your question. I appologize in advance for this wordy response but FDA clearance involves several key steps: 1. Pre-Submission Communication: It’s helpful to engage with the FDA early on to discuss the requirements for your product. This could involve a Pre-Submission meeting, where you get feedback on your development plan and the regulatory pathway. 2. Regulatory Classification: Determine whether your product falls under a specific FDA classification (e.g., Class I, II, or III). Class I devices have the least regulatory control, while Class III devices (like implants or life-support devices) require the most oversight. 3. Clinical Trials and Data: For devices that require more scrutiny, clinical trials may be necessary. This ensures the product is safe and effective for its intended use. This data is then compiled into a submission package for FDA review. - Animal Testing: One crucial step in the FDA approval process is conducting animal testing - in this project it was done on a pig :( - to assess how the product behaves in a biological environment. This helps to evaluate the safety of the coating when applied in a clinical setting, ensuring that it doesn’t cause any adverse reactions when in contact with body tissues. It also allows us to observe the product's durability and effectiveness over time in a living organism. - pH Testing: For a product that will be used in the body, pH testing is essential to ensure it is compatible with the body’s natural environment. The product needs to be within a safe pH range to prevent any irritation or tissue damage. KnoxFog™ is designed to be pH neutral, which is critical for maintaining compatibility with body fluids and tissues, and this has been a key part of our testing process. 4. FDA Submission: The most common submission is a 510(k), which shows that your device is substantially equivalent to an existing, legally marketed device. If it’s a completely new device with no equivalent, you might need to go through the Premarket Approval (PMA) process, which is more detailed. 5. FDA Review: Once submitted, the FDA reviews the data, clinical studies, and any other relevant information to ensure the product meets safety, efficacy, and manufacturing standards. They may ask for more information or clarification. Approval: If the FDA is satisfied, they issue clearance or approval, allowing the product to be marketed. I am sorry once again this response is so long but this just goes to show everyone how lengthy the process for commercialization is. I am glad to be a part of this journey and be able to see how technology goes from the lab into peoples hands. Thank you for listening!

February 20, 2025 at 2:22 pm - Reply

Anonymous

Thank you Shreyash for this well written introduction! I loved how you made a clear goal for this blog post and sectioned it out into easy-to-read key points. This made the information super easy to follow. The figures were a great touch too; they were a great help in visualizing the concepts and thinking about how I can apply them. Great work and I look forward to following your future research on KnoxFogTM!

February 20, 2025 at 7:45 pm - Reply

Shefali Prakash

Hi Shreyash, I really enjoyed reading about the history of the development of anti-fog solutions. I also thought the visuals were quite clear and informative. What are some other applications you can envision the anti-fog solutions being applied to?

February 24, 2025 at 9:23 am - Reply