From your fingertips to the compost heap: biodegradable electronics are coming!

- Montreal, Quebec

Organic farming. Carbon-neutral transportation. Bio-sourced materials. Composting organic waste. We recognize these as important contributors to a green economy, whose hallmark is sustainable development without degrading the environment.

However, toxic e-waste such as batteries, phones and computers can still end up in landfill where they add to environmental damage. But that is about to change with innovative technology that will make it possible to simply toss obsolete devices into bins for composting!

To that end, the National Research Council of Canada (NRC) is developing a new generation of green materials for electronic devices, and sourcing them from renewable natural resources. One of these is eumelanin, cuttlefish ink pigment, which will transform electronics into biodegradable products.

On the road to a green economy

The process for building a green economy has many moving parts, especially when it comes to the Internet of Things (IoT)—physical objects with sensors, processing ability and software that connect them to the Internet. As these micro-sensors, processors and other technologies become obsolete, they often end up littering the landscape or loading up landfills. According to the Global E-Waste Monitor, by 2030, global e-waste is expected to top 74.7 megatonnes (Mt).Footnote 1

The basis for a successful green economy is a circular economy. This model of production and consumption stops waste from being produced in the first place, circulates resources and regenerates nature.

Illustration depicting the process of the green economy: sharing, reusing, repairing, renovating and recycling existing materials and products for a greener planet.

According to Dr. Denis Rho, Applied Microbiologist in the NRC's Aquatic and Crop Resource Development Research Centre, important steps in establishing a circular economy include identifying materials that can be used to manufacture and package eco-friendly electronics such as batteries and sensors, and testing their biodegradability.

Canada alone produces approximately 31 million tonnes of waste a year and recycles only about 30% of itFootnote 2. But the NRC is looking for ways to improve those numbers. "Canada is full of underutilized biomass resources such as plants, marine algae, wood and animal waste," explains Dr. Rho. "We're developing green systems to extract them and apply them to new products." As part of this initiative, scientists and engineers from the NRC and the Department of Engineering Physics at Polytechnique Montréal are sourcing ingredients for green electronics, designing new products and testing them for end-of-life compostability.

From the sea to the compost heap

The NRC's collaborative research team is focusing on the half-life and biodegradation efficiency of ecomaterials. This increases the rate at which the compost microbiome degrades these materials and minimizes the time they spend in the industrial ecosystem. The design of organic electronics for standardized biodegradability will see composting become an alternative to landfilling.

The team has successfully biosourced and tested eumelanin, cuttlefish ink pigment, to use in green organic electronics. Eumelanin is an environmentally friendly material ideal for exploring the potential of sustainable organic electronics and its powering elements.

"For our research, we extracted the ink pigment in the lab and examined its electronic properties and behaviour," adds Dr. Rho. "We then buried it in the NRC bioreactors filled with a select compost material that is incubated for up to 100 days at 58℃ in our composting facility and monitored it for biodegradation."

Green organic electronics is an emerging field that, so far, has no national or international standards to evaluate their end-of-life biodegradability in industrial organic waste facilities. This NRC-Polytechnique project is the first of its kind providing data to help Canadian and international standards organizations develop new guidelines and test protocols.

Composting for tomorrow

As the research continues, Dr. Rho expects to explore other types of compost that feature different microbial communities.

But testing the biodegradability of these new eco-materials is only one aspect of his work. Dr. Rho's composting facility is also part of a unique industrial collaboration between the NRC and Xerox Canada. Led by Dr. A. Laforgue, of the NRC's Automotive and Surface Transportation Research Centre, and Dr. N. Chopra of the Xerox Research Centre of Canada, that project team is designing environmentally friendly batteries.

In addition, at the Aquatic and Crop Resource Development Research Centre lab, Dr. Rho studies chemotropism, an ecological means by which solid materials are colonized by microorganisms and biodegraded during the composting process. "This promotes the development of a second-generation composting process, which is essentially inspired by nature," he adds.

Understanding the compost microbiome should pave the way for the discovery of new microbes with specialized enzymatic capabilities, which are key to the efficient biodegradation of energy storage devices.

Dr. Rho isn't shy about sharing how important his research is for future generations. He says the research they are doing today in this field will determine whether or not there is a thriving future for our communities, our cities and the natural world around us.