E-waste, or electronic waste, is a growing global problem that’s getting worse as more new types of flexible electronics are produced.
These include devices for robotics, wearables, health monitors, and single-use gadgets.
To tackle this issue, researchers from MIT, the University of Utah, and Meta have developed a new flexible material that could make recycling electronics easier and more effective.
This innovation might also lead to the creation of more complex and layered electronic circuits.
The details of this breakthrough were published in the journal RSC: Applied Polymers by MIT Professor Thomas J. Wallin, University of Utah Professor Chen Wang, and seven other researchers.
“We recognize that electronic waste is an ongoing global crisis that’s only going to get worse as we continue to build more devices for the internet of things, and as the rest of the world develops,” says Wallin, an assistant professor at MIT.
Most flexible electronics today use a polymer called Kapton, known for its excellent thermal and insulating properties. It’s found in almost every electronic device, including the flexible cables in your cellphone or laptop, and is widely used in aerospace applications.
The global market for polyimide, the material Kapton is made from, is expected to reach $4 billion by 2030. However, Kapton has significant drawbacks: it’s nearly impossible to melt or dissolve, making recycling difficult, and it takes hours to process.
The new material developed by the research team is also a type of polyimide but with some key differences. It is similar to the polymers dentists use for fillings, which harden in just a few seconds under ultraviolet light. This means the new material can be processed quickly and at room temperature, unlike Kapton which requires high heat.
The researchers believe this new material could be used to create multilayered electronic circuits. Kapton’s resistance to melting means its layers must be glued together, adding time and cost. The new material’s ability to harden quickly at low temperatures could simplify this process, making it easier and cheaper to produce complex electronics.
In addition to its manufacturing advantages, the new material is designed to be recyclable. The researchers added special subunits into the polymer’s structure that can be dissolved by a mild alcohol and catalyst solution. This allows the valuable metals and microchips in the circuits to be recovered and reused.
“We designed the polymer with ester groups in the backbone,” Wang explains. These ester groups can be easily broken down, allowing the substrate to be removed while leaving the electronic components intact. Wang’s team at the University of Utah has even co-founded a company to bring this technology to market.
“We break the polymer back into its original small molecules. Then we can collect the expensive electronic components and reuse them,” Wallin adds. Given the current supply chain shortages for chips and materials, this recycling process could be both economically and environmentally beneficial. The rare earth minerals in electronic components are highly valuable, making this new material a promising solution for reducing e-waste and recovering precious resources.
This new material could be a game-changer in the fight against e-waste, helping to make electronics more sustainable and easier to recycle.
