Light accelerates conductivity in nature's 'electric grid'

The natural world has its own electrical grid composed of a global web of small nanowires in the soil and oceans.

Researchers at Yale University found that light is an ally in fostering electronic activity within the biofilm. They found that exposing the nanowires to light gave them an up to 100 fold increase in electrical conductivity.

The findings were published in September.

A stable and robust photocurrent can be seen in the dramatic current increases in nanowires.

As scientists try to find ways to exploit this hidden electrical current for a variety of purposes, the results could provide new insights.

Oxygen is the main source of energy for living things. Without access to oxygen, soilbacteria living deep under oceans or buried underground over billions of years have developed a way to respire by breathing minerals.

The researchers were surprised by the increase in electrical current when thebacteria were exposed to light. The previous studies showed that the growth ofbacteria was faster when they were exposed to light.

Malvankar said that nobody knew how this happened.

In the new study, a Yale team led by researcher Jens Neu and graduate student Catharine Shipps concluded that the metal-laden cytochrome OmcS acts as a natural photoconductor.

It is a different form of photosynthesis. Light is moving quickly through the air due to rapid electron transfer.

Malvankar's lab is looking at ways to spur growth in optoelectronics, a field that studies devices and systems that find and control light, as well as capture methane, a greenhouse gas that contributes to global warming.

Matthew Guberman-Pfeffer is one of the authors of the paper.