A clam shell for a television or smartphone screen? This isn't the Flintstones, but modern technology. Giant clams possess iridescent shells that may one day help scientists design more energy efficient and less glaring television and smart phone screens and solar panels.
Amitabh Ghoshal, an optical physicist at the University of California, Santa Barbara and his team are studying these giant clams, not dining on them, to see how their iridescent cells interact with algae to enhance photosynthesis. Some of the colors created by these clams put computer screens and cell phones displays to shame and the researchers wondered if they could discover the clams' secret and use it to enhance video technology.
These colorful giant clams are native to the coral reefs of the Pacific and Indian oceans. Their exposed flesh has iridescent cells which generate a variety of colors from shades of green and blue to gold and the seldom-seen white. No two giant clams have identical colors. The clams absorb nutrients from algae, while the algae live off the nitrogen-rich waster from the clams. Like solar cells, photosynthesis converts light into energy. Could the secrets of the giant clams be used to better solar cells as well?
The scientists focused on two clam species, Tridacna maxima and Tridacna derasa. In particular, they analyzed their rare white pigments and discovered that both species created the white hue by mixing colors together - a process very similar to how video displays mix red, blue and green to produce white.
Surprisingly, they found that the two species used different mixing methods to create white. Tridacna maxima’s white comes from tight clusters of iridocytes that each reflect different colors, much like clusters of RGB pixels that produce a white color. Tridacna derasa creates white from iridocytes that are multicolored but together look white from a distance.
What will Ghoshal and his team do with the knowledge they've gathered from the clams? Currently, LED’s are the primary light source for computer and phone displays. Their goal is to create and control structures similar to those on the clams to build color-reflective displays that work with ambient light like sunlight or indoor lighting. With the clam's ability to look so bright so deep under water, this should help develop screens that work better in low light conditions. Finally, by studying the efficiency of the clam's iridocytes, they hope to build more efficient solar cells, requiring less space that current rooftop panels and land-based solar farms.
Amitabh Ghoshal and colleagues Elizabeth Eck and Daniel Morse are collaborating with Guillermo Bezan, director of the Center for Polymers and Organic Solids at the University of California at Santa Barbara. Their complete study can be found in the journal Optica.
That's it, in a clam shell!