Yokohama National University resin can be recycled and reprinted 10 times

What if a failed SLA print did not become trash after the wash cycle? Yokohama National University says its anthracene-based resin can be melted back into a printable liquid and reprinted more than ten times with minimal degradation, a result that could make resin printing far less wasteful if it holds up outside the lab.

The team’s photocurable material is built around anthracene, a compound whose bonds respond to both light and heat. Under ultraviolet exposure, the resin hardens through photodimerization. When heated, the reaction reverses and the material returns to a printable state. Just as important for recycling, the formulation works without photoinitiators or other additives, reducing the contamination risk that has complicated earlier attempts to reuse UV-curable resins.

That matters because conventional stereolithography resins usually end up as disposable parts once they cure. The cross-linked polymer networks that give SLA and two-photon prints their detail also make them notoriously difficult to recycle. Yokohama National University’s paper, published online Feb. 21, 2026 in ACS Omega, points to that problem directly and frames the new resin as a way to keep high-resolution printing in a more circular workflow.

The researchers demonstrated the material in both single-photon microstereolithography and two-photon lithography, so this was not limited to one narrow printing mode. In one repeated test, they printed the letters YNU, erased them by heating, and printed them again across more than ten cycles. In another, a printed cube was heated to 150 degrees Celsius for 15 minutes and then reprinted as a disc. Those examples suggest the material can survive repeated reuse without quickly losing the characteristics that make resin printing attractive in the first place.

The paper was written by Masaru Mukai, Wakana Miyadai, Seina Matsubara, Tomomi Aoki, and Shoji Maruo, all at Yokohama National University. Maruo, a professor in the Faculty of Engineering and co-corresponding author, said earlier reusable resins either need chemical additives or break down after one or a few cycles. The university also notes that anthracene already has industrial uses in dyes, plastics, and wood preservation, which helps explain why it was chosen as the backbone for the resin.

For desktop users, the immediate takeaway is not a product page. It is a proof-of-concept that suggests failed prints, support-heavy jobs, and expensive specialty resin could one day be managed with far less waste. Before that reaches the average workshop, the material will need to prove it can scale beyond university systems and preserve the same repeatability in everyday printers. For now, the question is no longer whether resin printing can be recycled at all, but how close the hobby market is to a resin that can come back from the vat as cleanly as it went in.