Researchers have succeeded in transforming cellulose into porous, light and heat-insulating foam that can be dyed. In camouflage shades, the foam may be used for concealment during short-term field operations.
Soldiers, hikers and hunters could use the foam to conceal tents, vehicles or tanks.
Camouflage is used to make persons or objects blend into their surroundings. In nature as well as in clothing, the simplest method of camouflage is to use a pattern resembling something in the vicinity.
Today, however, just mimicking your surroundings visually is not enough. Advanced multispectral detection technologies make it possible to spot targets in many ways, such as monitoring heat radiation.
A study by Aalto University and the Häme University of Applied Sciences (HAMK) has used cellulose to produce a lightweight and porous foam, and lignin and green microalgae to dye the foam in forest shades.
The foam can be used for short-term camouflage in forest environments in more versatile ways than would be possible using just fabric.
Research on cellulose foams is plentiful, but using foams for camouflage is an innovation. The manufacturing process is simple and the foams are also good heat insulators, which makes it more difficult to detect the target with, say, infrared (that is, heat) detectors.
The study shows that cellulose-based wet foams stabilized with lignin and microalgae are low-cost and not toxic to the environment. After use, the foam is spontaneously composted in nature.
The study results provide a good basis for using the material in further development of camouflage.