New Self-Healing Plastic for 3D Printing Epitomizes Plastic Conundrum

Plastic is a bit reminiscent of the opening lines to A Tale of Two Cities: it’s the best of materials; it’s the worst of materials. Used for just about everything, and usable for seemingly any conceivable purpose, it also has a detrimental environmental impact in as many ways as we can think of (and probably in more ways than we’re currently able to imagine). At the same time, no matter how plagued humanity has been by our creation, it seems beyond unrealistic to think that, at this point, plastic could ever just “go away”.

This is, of course, one of the potentially promising angles to 3D printing: theoretically, wastefulness in the use of plastic in manufacturing processes could be minimized, by printing end-use parts on demand and at the point of end use; enhanced recycling efforts with circular economies; and, generally, more precise control over production techniques. Broadly, the idea is that we might as well start learning to manage our consumption as prudently as possible, if plastic isn’t going anywhere. Exactly the extent to which this material has dominated the human world is illustrated in a recent research project, by academics at Australia’s University of New South Wales (UNSW) School of Chemical Engineering.

Published the journal Angewandte Chemie International Edition, the team’s research involves “self-healing 3D printed plastic” (it is now apparently in good form to deem plastic deserving of selfhood). Although other versions of this technology have existed for some time now, as the research team’s spokesman, Dr. Nathaniel Corrigan, pointed out, “[The] other processes that do this [] rely on thermal chemistry to repair the material and typically it takes around 24 hours and multiple heating cycles to achieve the same result.” The uniqueness of the powdered additive used by the engineers at USNW — a reversible addition fragmentation chain transfer (RAFT) agent, which is mixed in with the liquid resin used in the 3D printing process — is that it “heals” simply by being placed under standard UV LED lights, and is fully repaired in about an hour.

Additionally, the damaged elements don’t have to be removed from the object of which they’re a part, then reattached once they’ve been fixed, as is the case with other technologies aiming to achieve the same purpose. Instead, as the team displayed on a 3D printed violin, the broken components can be left exactly where they are. The team even claims that the damaged plastic ends up stronger than before, which seems a bit eerily like the classic 50s movie monster The Blob.

This brings me to my conclusion, which is that, while the team claims that there “is an obvious environmental benefit” to the technology, I’m not so sure how “obvious” it is. The Jevons paradox, named for the 19th century English economist Stanley Jevons, would suggest, for one thing, that all this technology would do in the long run would be to help lead to ever-increasing use of plastic. For another, the more this type of plastic is used, the less recycling there would be, meaning that even if it, on its own, is less wasteful, it would nevertheless contribute to increasing wastefulness overall. Rather than a solution to wastefulness, this research project highlights exactly how intractable the problem is. The answer, in the long run, may lie more in developing as many decomposable alternatives to plastics as possible, rather than in any solution still trying to make plastic “more sustainable”.

Images courtesy of USNW School of Chemical Engineering