Micromotors to cleanse carbon dioxide from our oceans

Nanoengineers from the University of California in San Diego have created a microscopic motor that is designed to remove carbon dioxide from the ocean. With the acidification of the worlds’ oceans increasing, removing carbon dioxide from the ocean will hopefully lessen or reverse the effects of climate change in time. High levels of carbon dioxide in the water result in a decrease in aquatic life and water quality worldwide.  

These new “micromotors” will be on the leading edge in carbon dioxide reduction. The studies co-first author, Virendra V. Singh, says, “We’re excited about the possibility of using these micromotors to combat ocean acidification and global warming.” 

The University of California’s micromotors use an enzyme called carbonic anhydrase on an outer polymer to move around in water. It uses hydrogen peroxide as a type of fuel to power the enzyme. The hydrogen peroxide reacts with an inner platinum surface to generate oxygen bubbles. These bubbles in turn propel the carbonic anhydrase and move the motor.  

Because the platinum surface makes the micromotor expensive, researchers are planning for a way to make the motors propelled by water. “If the micromotors can use the environment as fuel, they will be more scalable, environmentally friendly and less expensive,” said Kevin Kaufmann, co-author of study.  

The carbonic anhydrase enzyme also acts as a means to reduce carbon dioxide in the water. It does so by speeding up the reaction between carbon dioxide and water, which turns the carbon dioxide into calcium carbonate. Calcium carbonate in a substance that makes up the bulk of seashells and limestone and is environmentally friendly.  

Each micromotor is 6 micrometres long and is completely autonomous. Once deployed in the water, they move along and “clean up” any carbon dioxide they come across. Due to the fast and continuous movement of the motors, they are very efficient. In the study’s experiments, the micromotors were able to move as fast as 100 micrometres per second, and they were able to remove 88 percent of carbon dioxide in a sea water solution in 5 minutes.  

Once these little motors are deployed in the ocean, they will continuously remove any carbon dioxide in the water and combat the effects of climate change in our oceans. With any luck, they can restore the health of our oceans and the aquatic life that resides in them.