Nanobubbles, tiny gas bubbles in liquids, have diameters of 1000 nm or less, with the ideal size for therapy falling within the ‘island of stability’ at 50 nm to 200 nm. On average, they measure about 100 nm, making them 500 times smaller than microbubbles. To provide context, an average human hair is 100,000 nm wide—1,000 times wider than a single 100 nm nanobubble.
Nanobubbles are considered an effective therapeutic because of their unique physical and chemical properties.
Physically, nanobubbles have the unique ability to remain in water for extended periods, lasting months or even years, in contrast to larger bubbles like microbubbles that dissipate within hours (similar to the rapid loss of carbonation in soda). This prolonged stability proves beneficial for producing packaged goods like oxygenated nanobubble water, such as O2n water . Moreover, the technical advantage lies in the ability to cycle the same water through the nanobubbler multiple times, thereby increasing nanobubble concentration—a crucial factor for therapeutic value. The enduring presence of nanobubbles in water can be attributed to several factors.
Nano-sized, nanobubbles balance buoyancy with gravitational forces, staying suspended in liquid for extended periods. In contrast, larger bubbles, with strong buoyant forces, rise and leave the water when blown, making coalescence detrimental to nanobubble lifespan and efficacy.
Due to their size, nanobubbles experience Brownian motion, a random motion in and around water that ensures even distribution.
Nanobubbles, with a strong negative charge, actively repel each other, preventing coalescence and influencing their stability, lifespan, and potential for higher concentrations. We’ve optimized nanobubbles’ physical properties for maximum therapeutic efficacy, with zeta potential playing a key role . The significant internal pressure within nanobubbles maintains their surface charge, preserving zeta potential and extending lifespan . Chemically, liquids like water have a saturation point for gas dissolution determined by partial pressure following Henry’s Law. Nanobubbles, not considered dissolved, act as separate oxygen-filled cavities, allowing them to supersaturate. Peer-reviewed articles show nanobubbles increasing partial pressure by over five times .
The following graph shows water saturated with nanobubbles vs microbubbles vs control. The partial pressure is highest (by a significant margin) for fine microbubbles/nanobubbles .
Notes: We generated oxygen fine micro/nanobubbles using a dedicated micro/nanobubble aerator, supplying oxygen gas at a rate of 1.5 L/minute for 15 minutes, followed by immediate brief sonication. Oxygen macrobubbles were produced in 150 mL of ultrapure water using porous ceramic, with an oxygen gas supply of 1.5 L/minute for 15 minutes. We measured the oxygen partial pressure in ultrapure water through blood gas analysis. The data represent the mean ± standard error of the mean from five separate experiments, each conducted in duplicate. **P<0.01.” 
This contrasts with microbubbles, which, for example, rise to the top of water and don’t offer much therapeutic value. In other words, nanobubbles can increase the water’s oxygen concentration by allowing it to contain its maximum dissolved oxygen content. Additionally, the oxygen in the nanobubbles themselves contributes to this effect, while microbubbles escape the water too quickly and, therefore, cannot contribute to transdermal oxygenation.
We detail this concept even more in our optimization article .
Nanobubble immersion therapy can be as simple as having a user lie in a tub of water saturated with nanobubbles. However, if done incorrectly, this approach will not yield any therapeutic value. Instead, at old.oval.bio, we focus on the two most important factors that can influence the efficacy of nanobubbles: the size and concentration of bubbles.
Size: Bubbles should consistently fall within a size range termed the ‘island of stability’—ranging from 50 nm to 200 nm. Bubbles smaller than 50 nm tend to collapse, transforming into dissolved oxygen. If the water is already at maximum saturation, the oxygen will merely escape. Conversely, bubbles larger than 200 nm tend to coalesce and subsequently escape the water rapidly.
Refer to the figures below to see the range of diameters our nanobubbler produces (mean 115.9 nm and mode 87.4 nm).
Using smaller nanobubbles allows for a greater oxygen volume saturation in water compared to traditional bubbles. Essentially, smaller bubbles enable higher oxygen concentration in the same space, akin to filling a bottle with sand instead of pebbles. Our nanobubbler achieves the advantageous goal of targeting the lower end of the stability island.
Regarding concentration, it’s widely acknowledged that when water’s oxygen levels surpass those in the body, absorption occurs through osmosis. Higher oxygen concentrations in water facilitate the transfer of oxygen into the body, increasing the quantity transferred. Nanobubbles enhance the dissolved oxygen potential, saturating the body with an increased quantity of oxygen.