researchers from the university of southern california (los angeles, calif.) viterbi school of engineering have developed a hybrid structure of silicon and vanadium dioxide that acts as a textured skin to self-regulate the temperature of satellites, according to an article on the usc website.
usc researchers are creating a "skin" to cool satellites.
as the article noted, temperatures in space have extreme variations and current methods for maintaining proper temperature using physical shutters or heat pipes can tax the satellite’s power reserves.
vanadium dioxide acts as a phase-change material, providing insulation in low temperatures and conducting heat in higher temperatures.
“at over 134°f (330°k), it radiates as much heat as possible to cool the satellite down,” the article explained. “at about two degrees below this, the material shuts off the heat radiation to warm the satellite. the material’s conical structure (almost like a prickly skin) is invisible to the human eye at about less than half the thickness of a single human hair, but it helps the satellite switch its radiation on and off very effectively.”
researchers insist that the material, which was developed in cooperation with aerospace and defense company northrop grumman, maintains temperature 20 times better than silicon alone.
the material has terrestrial applications as well. for instance, researchers believe that the material could be used for thermal management of a large area of a building.
the research was recently published by optica. the abstract read:
“humans and other warm-blooded mammals maintain their body temperature within a narrow range in a process called homeostasis. this ability to maintain an internal temperature, which is relatively insensitive to changes in the external environment or heat load is vital for all complex processes that sustain life.
“without the ability to regulate temperature, materials and devices that experience large temperature gradients or temperature cycles are vulnerable to performance degradation or even catastrophic failure. thermal control akin to the way living organisms achieve thermal homeostasis is particularly important in environments such as space, where changing solar illumination can cause large temperature variations.
“various systems have been used to mitigate temperature fluctuations; however, they tend to be bulky and require power. here, we model micropatterned phase-change materials to design an efficient, solid-state alternative, which requires no external input power.
“our design is based on switchable thermal emission, which takes advantage of temperature-induced phase-change behavior in thin films of vanadium oxide on silicon microcones.”