The world’s appetite for electronics is growing, but what happens when we are done with our old phones and tablets? Most electronics are not degradable, and their disposal contributes to a variety of environmental problems.
To help address this electronic waste problem, a University of Illinois research team led by D.K. Lee and Lisa Ainsworth is working to investigate the production and extraction efficiency of plant-based compounds that can be used to 3-D print biodegradable electronics. This research program, called the Bio-Based Chemicals Project, is part of a multi-institutional effort titled “Manufacturing ADvanced Electronics through Printing Using Bio-based and Locally Identified Chemicals (MADE-PUBLIC).” Funded by the National Science Foundation, MADE-PUBLIC is an interdisciplinary collaboration that brings together experts from the University of Chicago, the University of Illinois Urbana-Champaign, Argonne National Laboratory, Northwestern University, Iowa State University, and University of Illinois Chicago.
The MADE-PUBLIC team hopes to demonstrate a manufacturing paradigm that converts plant biomass into inks that can be used to print green electronic devices. Additionally, they aim to democratize the manufacturing of these electronic devices by enabling individuals to print their own devices.
“We’re using the lignin and cellulose content of plants to produce graphene and cellulose nanocrystals respectively,” said Kayla Vittore, a graduate student in Crop Sciences at Illinois and a member of the Bio-Based Chemicals Project’s operating team. “And those components can be used to make bio-based inks for a 3-D printing process that can produce biodegradable electronics.”
The Bio-Based Chemicals Project team is studying how a plant’s species and growth conditions influence its lignin and cellulose composition. This process will allow the team to determine the best conditions to produce bio-based inks.
To this end, Vittore is raising various plants, such as Miscanthus x giganteus, switchgrass, and fiber-industrial hemp, under different nutrient availability treatments. Once grown, the plants are harvested and analyzed. The research team is evaluating the plants’ cellular morphology, specifically the lignin and cellulose layers, to see if different nutrient treatments influence these structures. The ratios of lignin and cellulose are a determinant of both yield production and extraction efficiency, so these evaluations will inform the team’s strategies for optimizing the amount of bio-based ink that can be produced.
Among the biodegradable electronics that can be printed are precision agriculture sensors developed by the MADE-PUBLIC team. These electronics can be used to monitor the growth conditions of plants.
“We aim to create a closed production circle, where you can use plant products to make sensors that can monitor the air and water conditions important for plant growth,” said Lee, Co-PI of the Bio-Based Chemicals Project and Professor of Crop Sciences. “The sensors will allow users to optimize the plants’ production of lignin and cellulose, which can be used to produce more sensors and other biodegradable electronics. The goal of this project is to create renewable and accessible technology.”
The sensors, which are being developed with both small-scale home growers and large-scale factories in mind, can tell users information like “nitrogen is limiting growth” or “phosphorus is limiting growth.” Based on that information, users can apply fertilizers accordingly, which optimizes the system by increasing the amount of cellulose and lignin the plants produce.
The general public will have access to many different sensor designs to print. One exciting application of these sensors is for urban gardening. If someone is looking to address food deserts in cities, they would be able to print sensors to help them monitor the contents of the soil in their gardens.
In addition to helping growers and reducing electronic waste, MADE-PUBLIC also helps address the supply chain issues common in electronics manufacturing.
“If people are growing their own plants to produce the lignin and cellulose to print their own electronics, that’s a much shorter supply chain than the big systems we rely on right now,” Vittore said.
Shorter supply chains mean reductions in greenhouse gas emissions, as there’s less travel involved. Additionally, as we’ve seen during the COVID-19 pandemic, longer supply chains are more apt to collapse when disrupted.
MADE-PUBLIC is made possible by the combined efforts of experts from a wide variety of fields and institutions. While researchers at Illinois — who became partners with the help of iSEE’s proposal development office — are working to increase the production and extraction efficiency of lignin and cellulose, MADE-PUBLIC collaborators from different institutions are working on other vital parts of the production cycle, such as producing the 3-D printable ink, designing the sensors, and 3-D printing the sensors and other electronics.
“It’s been fun working with people from different disciplines,” Vittore said. “We’re always learning new things from each other, which is a good opportunity to grow our communication skills. And leaning on each other’s different specialties allows us to do much more than we could as an independent lab.”
Said Lee: “I was very surprised. For many projects like this, the principal investigators will connect across institutions, but the grad students not so much. But the MADE-PUBLIC grad students have been very collaborative and good at communicating across institutes and disciplines.”
It’s easy to be cynical about electronic waste, but with so many passionate researchers putting their heads together to solve this problem, there is hope.
“We’re trying to give people and companies the tools so that when they have the resources to do so, they can make sustainable choices,” Vittore said. “Many 3-D printers use unsustainable materials, like plastics, but if there are alternatives available, people can choose a more renewable source. Making sustainability accessible goes a long way.”
— Article by iSEE Communications Specialist April Wendling