As long as we depend on internal combustion engines, there will be oil spills like the one in May that blanketed beaches with black ooze in Santa Barbara, California. Compounding the injury, the chemical dispersants commonly applied to break up spills—like Corexit, widely used on the BP spill in the Gulf of Mexico—are highly toxic, sometimes more so than the oil itself, and have never been tested for human or environmental safety. 

An array of ingenious alternatives are in the works. By manipulating materials at the nanometer scale, David Lynn, a professor of chemical engineering at the University of Wisconsin-Madison, and assistant scientist Uttam Mannahave created a durable material that repels oil while allowing water to pass through. Lynn hopes that a meshlike structure coated with it could easily separate oil from water. 

Most natural substances absorb oil; those that repel it tend to also repel water because of water's higher surface tension. Dr. Anish Tuteja at the University of Michigan is working on a substance that repels oil but attracts water, possibly leading to a material that would keep the oil above a filter so that it could be poured or pumped off.

And Bharat Bhushan, a mechanical engineering professor at Ohio State University, replicates the water-repelling nanoscale roughness of a lotus leaf. By spraying silica nanoparticles on steel mesh, then covering that with a polymer embedded with a surfactant, he says, "you could potentially catch an oil spill with a net." 

The above approaches, while differing in elements and processes, all involve coating a fabric or mesh with a material that allows water to pass through but not oil. Researchers from the Sapienza University of Rome and Oak Ridge Laboratory are taking a different tack, working with carbon nanotubes to develop a "sponge" that slurps up oil and can be burned clean again and again.