Researchers have developed a new material, similar to what is used in dental fillings, that could help reduce tech waste.
E-waste is a serious problem: In 2022, the world produced 62 million metric tons of electronic waste-a category that includes anything with a plug or battery. That's expected to rise by 32 percent to 82 million metric tons in 2030, according to the United Nations Institute for Training and Research. E-waste recycling, however, isn't keeping up, and the report estimates that by 2030 only 20 percent of that waste will be collected and recycled.
One piece of research could help, though. In a paper published in July in the journal RSC Applied Polymers, researchers from the University of Utah, Massachusetts Institute of Technology, and Meta's Reality Labs detail a new material for the substrate-or the base layer of a computer chip or circuit board--that is both flexible and easily dissolvable. The fact that it's dissolvable means that other components attached to it can potentially be reused.
"This advance will enable high performance flexible electronic devices, while also solving the e-waste problem by enabling economic recapture of electronic components at end of life," Thomas Wallin, an assistant professor in MIT's Department of Materials Science and Engineering and one of the coauthors on the paper, wrote in an email.
One popular compound that is often used as a flexible substrate is a polyimide material with the trade name of Kapton. (Polyimide is a high performance plastic in the polymer family that can be used to replace glass and some metals, according to Omnexus.) Kapton's thermal and insulating properties make it a popular choice, but it can't easily be melted or dissolved, limiting its reusability, MIT News reported.
Wallin wrote that although Kapton "has been a fundamental building block in electronic devices for decades," its insoluble behavior "prevents both easy recycling/reprocessing of electronic devices (leading to the accumulation of e-waste) but also limits the processability in advanced electronic architectures with scalable workflows."
Flexible electronics are useful for both conventional technology like computers, as well as wearable tech such as devices for the internet of things and metaverse, Wallin noted.
In this case, the researchers' new material is similar to the polymer used to make dental fillings. It is processed at low temperatures, hardens quickly and can be cured with ultraviolet light. Because it is also a type of polyimide, researchers believe it will be compatible with existing manufacturing infrastructure and will aid in the manufacturing of more complex circuit configurations than current materials allow.
The material's reusability comes into play once circuits or chips have reached the end of their useful life. The new substrate material can easily dissolve "under mild conditions," leaving the chip's valuable metals behind, according to Wallin.