Meeting Abstract
S12-4 Monday, Jan. 7 09:00 - 09:30 Gecko-inspired composite microfibers for reversible adhesion on smooth and rough surfaces DROTLEF, DM; DAYAN, CB; SITTI, M*; Max Planck Institute for Intelligent Systems; Max Planck Institute for Intelligent Systems; Max Planck Institute for Intelligent Systems sitti@is.mpg.de http://pi.is.mpg.de
Nature offers inspiring strategies for strong and reversible adhesion in complex environments. For instance, geckos can adhere to rough surfaces with their adhesive pads covered by dense arrays of fine hairs. For the past decade, gecko-inspired micro/nanofibrillar adhesives have been extensively studied and principles of enhanced adhesion by contact splitting, equal load sharing or the mechanism of directional adhesion are well understood. Although artificial mimics demonstrate strong and reversible adhesion and even surpass the performance of the gecko on smooth surfaces, their adhesion on slightly rough surfaces is poor. Recently, alternative approaches inspired by animals´ seta with graded modulus, microfibers with soft tips and hard fibers, adhesive composite materials, and viscous systems directly crosslinked on rough surfaces have been demonstrated. However, their adhesion performance on rough surfaces are still questionable and not very reversible. In this study, we propose gecko-inspired composite microfibers with superior conformation and adhesion to smooth and rough surfaces. The adhesive patterns are composed of polydimethylsiloxane microfibers decorated with very soft and conformal composite mushroom-shaped tips. Tailoring tip geometry, layer thickness, tip composition, together with optimized processing parameters resulting in great surface conformation and enhanced performance. High adhesion strength of more than 200 kPa on smooth and 40 kPa on rough surfaces with high durability was achieved. The proposed composite microfibers enable the implementation of bioinspired patterns to various real world applications, inaccessible for current microstructured systems