Polymer from the Sea

There is nothing fishy about research on DNA as a biopolymer for photonics applications — except for the source material. Scientists at the US Air Force Research Laboratory and at the Universities of Dayton and Cincinnati, all in Ohio, have announced success in transforming DNA from salmon roe and sperm sacs into optical thin films.

Reporting in Applied Physics Letters 87, 211115 (2005), they said that the processed DNA shows low optical loss, high thermal stability and a molecular structure that may enhance chromophore alignment in poled polymer applications.

Moreover, it appears to be stable at temperatures up to 200 °C, and its raw material — fishing industry waste — is not only abundant, but also cheap.

The researchers have developed a conversion technique that involves treating the water-soluble fish detritus with a cationic surfactant to make it soluble in alcohol, dissolving it in butanol and depositing the filtered solution onto a substrate. The resulting soft films are crosslinked with PPIF to make them harder and less vulnerable to scratching.

The team is now investigating the electrical, optical and electro-optical properties of the stuff and are pursuing device applications. They believe that an all-DNA waveguide is possible and, perhaps, modulators and LEDs. Their work is an excellent illustration of “Waste not, want not.”