Called sweat transpiration technology, it utilises the natural function of sweat, which is to cool the body by removing heat as it evaporates from the skin surface, to keep the skin comfortable in hot environments.
Results of this research were presented at the 3rd Annual Congress of the Society of Cosmetic Chemists of Japan held in Kanagawa Prefecture from December 8 to 10, 2025.
“As the impacts of global warming on health and daily life become an increasing social concern, many people around the world experience discomfort caused by sweating in their everyday lives, such as stickiness and body odour.
“At the same time, sweating plays an essential role in thermoregulation by cooling the body as moisture evaporates from the skin. For this reason, rather than simply aiming to suppress sweat secretion, Kao has been conducting fundamental research into the nature of sweating itself, with the goal of maintaining skin comfort while preserving sweat’s original physiological function,” the company told CosmeticsDesign-Asia.
Conventional sweat-related technologies generally rely on antiperspirant salts that block sweat glands to prevent perspiration. In contrast, Kao’s approach to sweat care focuses on sweat’s inherent role in regulating body temperature.
“Instead of stopping sweating altogether, our technology aims to selectively reduce the discomfort associated with sweating. This concept is already being applied in Kao’s sweat care products. Going forward, Kao will deepen research into this area.”
Spread and dry
The research so far has found that substances such as sodium chloride in sweat make it harder to dry, and that the feeling of discomfort comes from sweat mixing with sebum.
Although porous silica (silicon dioxide containing countless tiny pores) were discovered to sodium chloride and sebum, excessive perspiration in hot environments causes sweat to remain on the skin when it does not dry completely.
Due to the hydrophobic nature of human skin, sweat tends to form droplets rather than spreading.
This inspired Kao to create a hydrophilic film on the skin to help rapidly spread sweat and accelerate the speed of evaporation. Its researchers tested various materials to identify one suitable to make the film.
Test specimens were applied to a plastic substrate, water was dropped onto them, and the contact angle was measured after 30 seconds. A smaller contact angle showed that water spreads more easily on the surface.
The test results indicated that when a certain hydrophilic plate-like powder was applied to the surface, the contact angle of the water droplets decreased.
Combining a certain hydrophilic plate-like powder with porous silica made the contact angle even smaller, indicating that water spread rapidly.
In addition, synthetic leather was used to mimic skin in experiments to confirm whether sweat would dry more easily if spread over a large area.
A prototype formulation containing hydrophilic plate-like powder and porous silica was applied to the synthetic leather, and artificial sweat (solution of sodium chloride and lactic acid in water) was sprayed onto it.
The evaporation time of the artificial sweat under the conditions of 30 degree Celsius and 60% humidity was measured. It was found that the time for the sample with the prototype formulation applied was approximately 33% shorter than the untreated sample.