He imagines building OFETs in hard gelatin capsules or on caramelized sugar for biomedical applications. Additionally, such materials could be nontoxic, unlike some of their inorganic counterparts, and they could take less energy to produce. Using biological materials to build electronics would be environmentally friendly, he says, in part because their ability to biodegrade would lead to less trash piling up. Beeswax and carnauba wax-derived from a species of palm tree-could make dielectrics that are also hydrophobic, which might be useful in some applications, Irimia-Vladu says. Many other biological materials could be transformed into suitable dielectrics, he says, including aloe, silk, and egg whites. Irimia-Vladu, a materials scientist at Joanneum Research in Weiz, Austria, has used cellulose as a dielectric layer in an inverter circuit and shellac as a dielectric in organic field-effect transistors.

“We have to be ashamed” of the amount of e-waste humanity produces, Mihai Irimia-Vladu told a symposium on organic bioelectronics at the December meeting of the Materials Research Society, in Boston. One way to lessen the problem, some scientists say, may be to use biological materials-including plant dyes and DNA-to build devices that are biodegradable and biocompatible. The United Nations estimates that people throw away about 50 million metric tons of electronics every year.

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