Temperature-sensitive hydrogel (TSHG)

a smart macromolecular material releasing moisture automatically when its temperature exceeds the lower critical solution transition temperature (LCST)

has been used for transpiration cooling

mimicking the thermoregulation mechanism of living creatures.The temperature and humidity distributions and heat dissipation characteristics of the TSHG transpiration cooling were measured experimentally using laser interference technique.A numerical model was established and verified with the experimental results.With the numerical model

the effects of environmental temperature

environmental humidity and LCST on the heat dissipation capability of TSHG were further studied.Results show that the cooling of TSHG can quickly lower the temperature of the specimen

with a heat transfer coefficient 15 to 25 times larger than that with common passive heat dissipation methods (natural convection and thermal radiation).The heat transfer coefficient can be significantly increased with the increase of environmental temperature and LCST

and may be slightly declined with the increase of environmental humidity.With the high heat dissipation rate without using a fan

the TSHG transpiration cooling is promising for the thermal management of mobile phones and other portable microelectronics.