Self-healing materials: a pathway to immortal products or a risk to circular economy systems?

Product lifetime extension is key strategy for a functioning Circular Economy. Yet, the role of material innovation and how this might contribute to longer product and material lifetimes has not been widely discussed. Considering the significant environmental burden of material resource extraction, the longevity of materials must also be deliberated. Inspired by biological systems, self-healing materials are a type of smart material with the ability to inherently repair themselves when damaged. Although a technology extensively investigated within the material science community, the Circular Economy and product lifetime extension implications of implementing these into products has yet to be debated. Thus, this empirical study investigates: What are the benefits, opportunities, risks and challenges for applying self-healing materials to products within the context of the circular economy? In addition to a literature review, this research was carried out utilising a survey, two round table discussions, a workshop and interviews with industry experts from several different sectors. Through thematic analysis, it was discovered that the key benefits that self-healing materials might offer to circular systems are: the ability to maintain the primary lifetime of the product from both a technical and service lifetime perspective; assistance in the refurbishing and remanufacture of products through increasing the ease of disassembly and reassembly of products; and the potential to enable alternative business models. The key risks and limitations are: issues of persistence within the system; hybridization of materials - technosphere or biosphere? whether they will cycle in the system; limitations regarding their technology development, performance and lastly queries of their liability and compliance. These findings are valuable to both fields of self-healing materials and circular economy, and they not only demonstrate what sustainability factors must be understood when developing novel self-healing compositions but also expand our understanding for how these materials might be utilised to create longer lasting products from an industrial perspective. The paper concludes with a set of recommendations for future research activities which could not only help to advance the field of self-healing but also potentially product longevity and make immortal products a reality.