MIT and Utah innovate flexible electronics material for efficient e-waste recycling

The rising challenge of electronic waste (e-waste) is set to intensify as the world adopts more flexible electronics for applications like robotics, wearables, and health monitors. Addressing this, researchers from MIT, the University of Utah, and Meta have developed a new flexible substrate material that could significantly reduce e-waste by enabling the recycling of materials and components from electronic devices. This new material also supports the scalable manufacture of complex multilayered circuits, surpassing the capabilities of existing substrates.

Described in the journal RSC: Applied Polymers, this breakthrough by MIT Professor Thomas J. Wallin, University of Utah Professor Chen Wang, and their colleagues presents a significant step forward in sustainable electronics. Wallin highlighted that the current approach to electronic waste is unsustainable, given the surge in devices connected to the internet of things (IoT) and the ongoing global development. Most research in this field has focused on alternative polymer materials, but these have not matched the commercial viability of existing materials like Kapton, a widely used polyimide.

Kapton, known for its excellent thermal and insulating properties, is projected to be a $4 billion market by 2030. It is extensively used in electronics and aerospace applications. However, its resistance to melting or dissolving makes recycling difficult and limits its use in advanced electronics manufacturing.

The new material, a form of polyimide developed by the research team, offers a solution. It is a light-cured polymer that hardens quickly under ultraviolet light at room temperature, in contrast to the traditional Kapton, which requires heating to 200–300 degrees Celsius over several hours. This new material can serve as a substrate for multilayered circuits, simplifying the manufacturing process and reducing costs.

In terms of recyclability, the team has introduced subunits into the polymer backbone that can be easily dissolved by a mild alcohol and catalyst solution. This process allows for the recovery of valuable components like precious metals and microchips, which can be reused in new devices. The polymer’s design includes ester groups that can be broken apart by the solution, leaving the rest of the device intact.

The University of Utah team is already moving towards commercialisation, having co-founded a company to bring this technology to market. Wallin emphasised the dual economic and environmental incentives of this innovation, particularly in light of ongoing supply chain shortages and the increasing value of rare earth minerals.

This development represents a significant advancement in the field of sustainable electronics, with the potential to reshape how e-waste is managed and recycled globally.