Talk about your unlikely combinations. Andrew Steckl, an expert in photonics from the University of Cincinnati, has been working to intensify the properties of LEDs by using biological materials - specifically DNA from salmon sperm. As he put it: "Biological materials have many technologically important qualities — electronic, optical, structural, magnetic. But certain materials are hard for us to duplicate, such as DNA and proteins."
Which is where the salmon sperm comes in: "Salmon sperm is considered a waste product of the fishing industry. It's thrown away by the ton. It's natural, renewable and perfectly biodegradable." He is quick to point out, however, that other plant or animal sources could prove equally useful. But why even use DNA in the first place?
Steckl believes that manipulating the motility of the electrons that help generate the LEDs' light could reveal new properties - properties that would ideally drive down costs to the producer, consumer and the environment and that would give a boost to performance. His BioLEDs, which incorporate DNA thin films as electron blocking layers, were the result.
"DNA has certain optical properties that make it unique. It allows improvements in one to two orders of magnitude in terms of efficiency, light, brightness — because we can trap electrons longer. Some of the electrons rushing by have a chance to say 'hello,' and get that photon out before they pass out. The more electrons we can keep around, the more photons we can generate. DNA serves as a barrier that affects the motion of the electrons."
Controlling these photons allows him to also control the brightness of the BioLEDs. Now that he's receiving salmon sperm in the truckloads from researchers and companies around the world, Steckl is ready to move on to his next objective: replacing other materials that go into a LED with biomaterials. He hopes to one day see "green" devices that incorporate biodegradable and renewable substances replacing all our conventional electronics. He may be on to something.