Fig. 3: Steady-state evaporation test of the i-Cool (Cu) textile, cotton and Dri-FIT.

a, Schematic illustration of the measurement apparatus and method. b, Measured water mass gain ratio (W) at different evaporation rate (v). Triangle, Statistical significance between the i-Cool (Cu) and cotton, Welch’s t-test p < 0.1 at 0.3 mL/h, p < 0.001 at 0.7 mL/h, p < 0.01 for others. Diamond, Statistical significance between the i-Cool (Cu) and Dri-FIT, Welch’s test p < 0.05 at 0.3 mL/h, no statistical significance at 0.5 mL/h, p < 0.01 for others. c, dW/dv obtained by fitting data in (b). i-Cool (Cu) can achieve a certain evaporation rate with much lower water gain. The required water gain increase for larger evaporation rate is also reduced. d, Measured power density (q) at different evaporation rate (v). Triangle, Statistical significance between the i-Cool (Cu) and cotton, Welch’s t-test p < 0.05 at 0.3 mL/h, p < 0.001 at 0.7 mL/h, 0.9 mL/h, p < 0.01 for others. Diamond, Statistical significance between the i-Cool (Cu) and Dri-FIT, Welch’s test shows no statistical significance at 0.3 mL/h, p < 0.05 at 0.5 mL/h, p < 0.01 at 0.7 mL/h, 0.9 mL/h, p < 0.001 for others. e, dq/dv obtained by fitting data in (d). The i-Cool (Cu) can show enhanced cooling effect with higher sweat evaporative cooling efficiency. All the error bars represent standard deviation of measured data.