Plant leaves are the ideal model for a lot of solar technology, so it only makes sense that developers of manmade solar panels would look to Mother Nature to improve the efficiency of their designs. Over time, solar cells wear down — just like leaves — due to degradation caused by ultraviolet light. A team of researchers from North Carolina State University revealed this week that they have created a new type of solar cell that can repair and reinvigorate itself by mimicking the functioning of organic vascular systems found in nature.
Biomimicry is a hot topic in the design world these days, especially in the field of solar technology, where researchers are striving to produce solar cells that function as efficiently as plant leaves. In nature, “branching” vascular channels are able to deliver life-sustaining nutrients throughout leaves — similar to the veins that run through your hand — restoring them to full health when parts of a leaf have been degraded by UV light. The researchers at North Carolina State University sought to replicate those processes and apply them to a new type of solar cell that is based on natural systems.
For its regenerative solar cell, the NC State team used natural materials that are cheaper and more eco-friendly than the standard silicon-based solar cells. The researchers produced dye-sensitized solar cells that are composed of a water-based gel core, inexpensive organic dye molecules, and electrodes.
“Organic material in DSSCs tends to degrade, so we looked to nature to solve the problem,” explains researcher Orlin Velev. “We considered how the branched network in a leaf maintains water and nutrient levels throughout the leaf. Our microchannel solar cell design works in a similar way. Photovoltaic cells rendered ineffective by high intensities of ultraviolet rays were regenerated by pumping fresh dye into the channels while cycling the exhausted dye out of the cell. This process restores the device’s effectiveness in producing electricity over multiple cycles.”