In 2011, the first cost-effective, stable artificial leaves were created, and in 2013, the devices were improved to self-heal and work with impure water. Now, scientists at Harvard have developed the "bionic leaf 2.0," which increases the efficiency of the system well beyond nature's own capabilities, and used it to produce liquid fuels for the first time.

The project is the work of Harvard University's Daniel Nocera, who led the research teams on the previous versions of the artificial leaf, and Pamela Silver, Professor of Biochemistry and Systems Biology at Harvard Medical School.

Like the previous versions, the bionic leaf 2.0 is placed in water and, as it absorbs solar energy, it's able to split the water molecules into their component gases, hydrogen and oxygen. These can be harvested and used in fuel cells to generate electricity, but now, with the help of an engineered bacteria, the hydrogen can be used to produce liquid fuels.