Feasibility of perspiration based infrared Camouflage

Infrared camouflage without resorting to existing and often burdensome technologies is clearly attractive. In this paper, we explored a new approach to potentially achieve the infrared camouflage by facilitating the latent heat transfer while controlling the sensible heat transfer of the human body. A multilayer structure of the corresponding camouflage cloth prototype with specific functions for each layer is proposed here (layer I to layer IV, from the body skin to the outside, respectively). Since the requirements for cloth infrared camouflage at steady state are much stricter than at transient period, a steady state model for this prototype is developed to test its feasibility. The influences of related key parameters, including the porosity and the thickness for each layer are discussed using the model. The results show that a satisfactory infrared camouflage may be accomplished using all the layers proposed under specified structural conditions. In order to achieve the best effect of camouflage, for example, when the environment temperature is 296.15 K with 30% relative humidity, we further discovered that (1) the porosities of layer I and layer II should be lower as 5%, but those of layer III and layer IV should be relatively higher (85% and 90%, respectively); and (2) the thickness of the second layer should be greater enough to 1.5 cm, but the thickness of layer IV must be sufficiently thin at 0.1 cm. In summary, our proposed prototype provides a promising design for the uniform that can be used to suppress the probability of infrared detection.