Abstract
For the next generation of handling systems, reversible adhesion enabled by micropatterned dry adhesives exhibits high potential. The versatility of polymeric micropatterns in handling objects made from various materials has been demonstrated by several groups. However, specimens reported in most studies have been restricted to the laboratory scale. Upscaling the size and quantity of micropatterned adhesives is the next step to enable successful technology transfer. Towards this aim, we introduce a continuous roll-to-roll replication process for fabrication of high-performance, mushroom-shaped micropatterned dry adhesives. The micropatterns were made from UV-curable polyurethane acrylates. To ensure the integrity of the complex structure during the fabrication process, flexible templates were used. The compression between the template and the wet prepolymer coating was investigated to optimize replication results without structural failures, and hence, to improve adhesion. As a result, we obtained micropatterned adhesive tapes, 10 cm in width and several meters in length, with adhesion strength about 250 kPa to glass, suitable for a wide range of applications.
Highlights
Micropatterned surfaces have attracted considerable attention as dry adhesives because of their remarkable adhesion performance
Process-material integration for a continuous roll-to-roll fabrication and excellent adhesion properties were realized by appropriate material selection, namely, UV-curable UA16 as material for the adhesive and ePDMS for the flexible template
Fabrication of mushroom-shaped microstructures exhibiting re-entrant features is possible by utilization of flexible templates
Summary
Micropatterned surfaces have attracted considerable attention as dry adhesives because of their remarkable adhesion performance. For the rational design of synthetic micropatterned surfaces, several aspects must be considered, such as pillar dimension and tip geometry, bulk material property, backing layer thickness as well as the rigidity of the target substrate [4,5,6,7,8]. The terminal tip of micropillars forming contact with the substrate is essential for high adhesion. Mushroom-shaped tips have been found to outperform other geometries by significantly increasing pull-off stress and work of separation [4,5,9,10,11,12,13,14,15]. The magnitude of stress singularities at the corner of the adhesive contact can be reduced in the mushroom tip design compared to non-optimized flat punch structures [16,17,18,19]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
