New adhesive system makes a circuit board that is 90% recyclable

Three British companies have developed a 90% recyclable and reusable circuit board, whose components can be easily separated by soaking in hot water. Funded by the UK government's

Technology Strategy Board with a view to help industry conform to European electronic waste regulation, the National Physical Laboratory (NPL), In2Tec and Gwent Electronic Materials have

devised an adhesive that helps manufacturers take apart electronic circuit boards and reuse their components to make new components. They call it ReUse – Reusable, Unzippable, Sustainable

Electronics. "What happens to end of life electronics is one of the fastest growing waste streams," says Chris Hunt, head of the Electronics Interconnection Team at NPL.

"Existing electronic circuit assemblies are based on reinforced epoxy glass systems and solder. A circuit board itself is a significant part of a final product but it's made with a

thermoset of glass that isn't easily recyclable. We looked at how you might make a circuit assembly that could disassemble easily when you no longer had a use for that appliance. The

result was a new adhesive and ink system, which allows the team to put components onto a thermoplastic substrate with a conductive adhesive and make a circuit. A substrate is a solid onto

which another solid is applied and that solid adheres to the first. A thermoplastic is something quite pliable at high temperatures but cools down to a rigid solid. The thermoplastic

substrate produced by the team can be recycled. The novelty of what NPL and its partners have developed is demonstrated when a circuit is exposed to water that is just about boiling. In the

presence of hot water the ink and the adhesive soften so significantly that all the components on the circuit are easily scraped off with a business card and can be reused for new circuits.

It seems laborious and Hunt agrees that they've a while to go before their innovation becomes scaleable for use by the likes of Apple or larger electronics manufacturers. "This is

definitely not a solution for all types of electronic technologies," Hunt continues, agreeing that some types of tech such as high-end servers and performance electronics operate at

temperatures too high for ReUse. However, their business partner In2Tec has already gained a few clients in the automotive industry off the back of this technology.." Hunt says

"there would have to be a step-change in a manufacturer's mindset to embrace this technology and until there is legislative pressure to change, they will stick with what they know.

What you get with ReUse is the ability to take apart and recover your components and reuse them. But until there is a pressure to change, manufacturers will stick with what they know."

NPL and its partners say they haven't used any restricted elements or compounds and around 90% of what they have constructed can be reused. "It's very difficult to throw away

much," says Hunt. "And when you look at how they currently make things, that's huge." _The design hub is funded by Nike. All content is editorially independent except

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