In the automotive industry, adhesives that combine high bonding strength with easy disassembly have long been in demand. However, conventional adhesives̶including epoxy-based adhesives-offer strong adhesion but are difficult to dismantle, making them unsuitable for such applications. Here, we report a bio-based adhesive derived from β-（1,3）-glucan（paramylon）sourced from Euglena gracilis, which achieves a tensile shear strength of 30 MPa on aluminum substrates̶substantially higher than that of conventional bio-based adhesives. Remarkably, this adhesive also offers exceptional circularity: bonded components can be easily disassembled by simple heating, allowing manual separation, and the adhesive can be reused repeatedly by re-laminating and reheating the adherends, fully restoring its initial strength. This study represents the first demonstration of a bio-based adhesive that simultaneously fulfills the key requirements for automotive applications: high bonding strength, facile disassembly, and reliable reusability.
Shibakami et al. (2026) studied this question.