Tiny, specially coated machines may become the environmental tool of the future in cleaning up oil spills, University of California – San Diego researchers report.
UCSD Nanoengineering Professor Joseph Wang and colleagues have developed and successfully tested the first self-propelled “microsubmarines” designed to zip through contaminated waters, picking up droplets of oil and whisking them off to collection facilities.
|Dr. Joseph Wang’s specially coated microsubmarines have demonstrated “facile, rapid and highly efficient collection of oils in oil-contaminated water samples.”|
The tiny machines could one day play an important role in cleaning up oil spills like the 2010 Deepwater Horizon disaster in the Gulf of Mexico, the team reports in a recent issue of the journal ACS Nano.
The technology is similar in some ways to drug delivery microengines that transport medications through the bloodstream. But no one has ever shown that these devices—which are about 10 times smaller than the width of a human hair—could help clean up oil spills.
To enable the subs to cover greater distances, the team had to dramatically decrease the engines’ fuel consumption and increase their speed. The devices are propelled by bubbles generated from the oxidation of hydrogen peroxide in their interior.
The invention marries Wang’s research in nanomachines—his research group has built the fastest nanomotors to date—with dodecanethiol self-assembled monolayers (SAMs), a “superhydrophobic” coating that repels water and absorbs oil.
A video shows the microsub in action.
“There is an urgent need for better ways of separating oil from water in the oceans and inside factories to avoid releasing oil-contaminated water to the environment,” UCSD reports in an article on the research.
Testing by Wang’s team showed that the cone-shaped microsubmarines, which require little fuel and move ultrafast, can collect droplets of olive oil and motor oil in water and transport them cleanly through the water.
American Chemical Society
|The simple nanomachine-enabled oil collection method is based on modifying tiny engines with a superhydrophobic coating that absorbs oil.|
“These results demonstrate the potential of the superhydrophobic-modified microsubmarines for facile, rapid and highly efficient collection of oils in oil-contaminated water samples,” say the researchers.
Tweaking the amount and composition of the coating can increase or decrease the strength of the subs’ attraction to oil. But the tiny propulsion mechanism would need additional development in the face of an oceanic massive spill.
“Practical large-scale oil clean-up operations would require the use of motors propelled by their own natural environment or driven by an external magnetic or electric field,” the researchers write.
The research was supported by funding from the National Science Foundation, NATO Science for Peace and Security Program, Spanish MICINN, Beatriu de Pinós (Government of Catalonia) and University of Alcalá (Madrid).