Scientific American profiles the creators of "Greensulate", an organic insulation made from rice hulls, recycled paper, and fungus:
They incorporated three basic ingredients in a solution of water and hydrogen peroxide: mycelium mushroom roots; perlite, a glassy volcanic mineral used by farmers to aerate soil; and recycled paper. They poured the mixture into a seven-by-seven-inch (17.8 centimeters) plastic container and stuck it under a bed in their apartment (Greensulate must be kept in the dark while it is growing). The mycelium fed off the natural sugars in the recycled paper, causing it to grow, tightly bind the perlite, and take the shape of the plastic container. The perlite created small insulating air pockets within this new rigid, beige-colored panel, which they then baked at 110 degrees F (43.3 degrees C) to remove all water from the finished product and assure that mold and spores do not photosynthesize. Bayer and McIntyre also experimented by replacing perlite with rice hulls, which form similar air pockets. The rice hulls are roughly 10 times cheaper than perlite. Greensulate panel of any size can be grown in five to 14 days, Bayer says, and will last for the life of the building in which it is installed. Manufacturing space should come relatively cheap because all Bayer and McIntyre need is someplace big and dark. "It could be an old Kmart," McIntyre says, "or even an abandoned mine shaft."More directly germane to consumer electronics, the company is also developing "Acorn", a compostable packing material.