In the US, about 10 million tons of new electronics entered the market in 2012. According to a recent study the United Stated topped the chart in terms of e-waste generated per resident at a staggering 65.5 pounds of e-waste produced per person each year. In an effort to alleviate the environmental burden of electronic devices has brought a team of University of Wisconsin-Madison researches together with researchers based in the U.S. Department of Agriculture Forest Products Laboratory (FPL). The result? A biodegradable semiconductor chip made almost entirely out of wood.
In a paper published on May 26th, 2015, the research team demonstrates the feasibility of replacing the substrate, or support layer, of a computer chip, with cellulose nanofibril (CNF), a flexible, biodegradable material made from wood. CNF is basically paper made from wood fibers at the nano-scale. In addition to being flexible — the gold standard for electronics parts these days — it is also very strong and transparent.
“The majority of material in a chip is support. We only use less than a couple of micrometers for everything else,” says Zhenqiang “Jack” Ma, lead electrical and engineering professor of the research team. “Now the chips are so safe you can put them in the forest and fungus will degrade it. They become as safe as fertilizer.”
While the biodegradability of these materials will have a positive impact on the environment, Ma says the flexibility of the technology can lead to widespread adoption of these electronic chips.
Zhiyong Cai, project leader for an engineering composite science research group at FPL, has been developing sustainable nanomaterials since 2009. The group’s work also demonstrates a more environmentally friendly process that showed performance similar to existing chips. The majority of today’s wireless devices use gallium arsenide-based microwave chips due to their superior high-frequency operation and power handling capabilities. However, gallium arsenide can be environmentally toxic, particularly in the massive quantities of discarded wireless electronics.
While the biodegradability of these materials will have a positive impact on the environment, Ma says the flexibility of the technology can lead to widespread adoption of these electronic chips.