Enhanced Reversible Adhesion of Dopamine Methacrylamide-Coated Elastomer Microfibrillar Structures under Wet Conditions

Abstract

In this work, we take previously developed gecko-foot-hair-inspired elastomer microfiber arrays with film-terminated and mushroom-shaped tips that have demonstrated enhanced adhesion with respect to unpatterned materials under dry conditions and coat them with synthetic DOPA-containing mussel-inspired polymers to enhance adhesion repeatedly in fully submerged wet environments. A new protocol for the development of this hybrid patterned, coated adhesive, which is suitable for use in contact with both wet and dry nonflat surfaces, is described. The experimental evaluation of repeatable adhesion under both wet and dry conditions for these materials is described and compared with unpatterned and/or uncoated materials. Macroscale reversible fibrillar adhesion enhancement on a nonflat, smooth glass surface when compared with unpatterned materials under fully submerged conditions is demonstrated with no suction effect.

Transfer Printing of Metallic Microstructures on Adhesion‐Promoting Hydrogel Substrates

“…These data suggest that P(HEMA-co -DMA) dissipates more energy through viscous responses compared to P(HEMA) hydrogel substrates and therefore requires relatively more tensile work for delamination. [ 46,74 ] The observed relationship of W HEMA-co -DMA-Au ~ 3 W HEMA-Au could be due to increased interfacial bonding and viscous dissipation in catechol-bearing hydrogels. The values of W HEMA-co -DMA-Au and W HEMA-Au were also measured as a function of preload force (Figure 2 c).…”

“…[43][44][45][46] Catechols bond to inorganic/organic materials in hydrated environments through polarizable aromatic groups, hydrogen bonds, and coordination bonds. [47][48][49] Hydrogels synthesized from nontoxic poly(2-hydroxyethyl methacrylate) (P(HEMA)) and polyethyleneglycol precursors [ 50 ] are materials that comprise biomedical devices used in human trials for many applications including controlled release matrices, [ 51,52 ] soft contact lenses, [ 53,54 ] and artifi cial corneas.…”

Recent Progress of Mussel‐Inspired Underwater Adhesives

“…In this figure, catechol, [22] dopamine [23] or dopa [24] was coupled to polymer chains ends or as side chains of polymerizable catechol monomers with the linear or branched polymer backbone, which are commonly made of polystyrene, [25] poly(ethylene glycol), [26] poly-(acrylate/methacrylate), [27] or poly(acrylamide/methacrylamide) [28] ( Figure 3). It is demonstrated that both of catechols and cations have a classic synergy for underwater adhesion.…”

Design of gecko-inspired fibrillar surfaces with strong attachment and easy-removal properties: a numerical analysis of peel-zone

“…The use of micro-and nano-structured fibrillar surfaces to mimic gecko seta arrays has attracted much interest during the past decade [9,12,[21][22][23][24][25][26][27][28]. Micro-fibrillar surfaces that use microfabricated hole array masters [2,9,10,21] and a nanowire surface with a larger aspect ratio and a high Young's modulus [7] have also been fabricated.…”