Adhesions based on direct covalent bond formation or host-guest interaction have been investigated.Suzuki-Miyaura cross-coupling, azide alkyne cycloaddition（ CuAAC） and Sonogashira cross-coupling reactionswere employed to realize direct adhesion of materials via very thin adhesive layer. These methods couldbe applied by using other chemical reactions to form covalent bonds between any kind of materials. Hostguestinteractions by using cyclodextrins（ CDs） were also used for adhesion. Cross-linkings by host-guestcomplexations were found to bind materials having host or guest moieties on their surface. The adhesionbased on host-guest chemistry showed selective bonding between various materials. And, the adhesions arecontrollable by using stimuli responsive guest moieties on the surface of materials. Rupture stress of thehost-guest bonding was found to be higher than that of covalently cross-linked adhesion because of theirsupramolecular structure in adhesive layer. Furthermore, the host-guest adhesion was found to have selfhealingproperty due to reversible nature of host-guest cross-linking. These adhesions would contribute to thevarious field of engineering using materials that conventional bonds cannot adhere.
