A new-type liquid crystal elastomer (LCE) has been developed, with the potential for application in PV cells to boost the latter’s conversion rate, thanks its phototropism feature.
The technology has been developed by researchers at Wyss Institute of Harvard University, who first manage the molecular arrangement of LCE via magnetic field (exposure to different magnetic fields would lead to different molecular arrangements) and wait for solidification of the structure before subjecting the LCE to the external stimulation of heat, light, and humidity, which would give birth to various shapes with different molecular arrangements (as shown in the following figure), greatly increasing usable space.
The technology represents a breakthrough, as with existing technology LCE has only limited changes in shapes, due to the confinement to one- or two-dimensional surfaces. Scientists have been striving to produce LCE in the pattern of the spatulae of lizards, which can easily stick to wall or ceiling thanks to the attachment force of the numerous spatulaes, to the tune of some 1 billion, on the millions of cilia on the toes of lizards.
Shapes of LCE can be changed upon heating (photo courtesy of Wyss Institute of Harvard University)
LCE is applicable to PV cells, thanks to its elastic feature, which enables it to regain original shape, once external stimulation disappears.
The research team of Wyss Institute tried to incorporate photosensitive cross-linking molecule into LCE structure, in order to make the shape of LCE change along with change in light. Researchers discovered that LCE would contract on the side which is exposed to light, forming a shape bent towards light. Therefore, covered by a LCE layer, solar panel would track sunlight, like a sunflower, maximizing exposure to sunlight, without the need of an auxiliary sun-tracking system.
The technology can also be applied in sensors and the foundation of smart buildings, as well as many other potential fields. The study has been published in PNAS (Proceedings of the National Academy of Sciences of the United States of America) journal.