Surface Design Of Flexible Material And Research On Adhesive Property

The amazing natural adhesive phenomenon gives us many inspirations on the research ofadhesive property. The penetrating groove, observed from tree frog toe pad, has been found to have aclose relationship with frog’s special adhesive property. The adhesive mechanism became one of thehotspot in recent years. As flexible material is more and more important in industry, the adhesivephenomenon has become an inevitable factor to be considered in the industry design. So it issignificant to control the adhesion.In this research, we used Polydimethylsiloxane (PDMS) as the experiment material. Differentgrooves and textural density were fabricated by Ultraviolet Lithography (UV-LIGA). The UMT wasemployed to test the adhesion of different contact pairs consisting of GCr15/PDMS and PDMS/PDMSrespectively. The adhesive mechanism was researched and discussed in this paper. The mainconclusions followed:1. Different contact situations had a strong influence on the adhesive property of PDMS. Whenthe contact situation changed from dry to wet condition, the adhesion force increased as meniscusforce was formed. When the volume of deionized water increased which was disadvantage ofmeniscus, the adhesion decreased.2. The adhesion from non-penetrating groove was stronger than penetrating groove. In threekinds of conditions, as the pit in non-penetrating groove had the “sucking disc effect”, thenon-penetrating groove can form stronger adhesion than penetrating groove. But the differencebetween two kinds of grooves decreased when the volume of deionized water increased from2μL to50μL.3. Two kinds of contact surfaces had the strong influence on the adhesive experiment. First, whenthe contact pairs were PDMS/PDMS, optimum density about adhesion existed when density changed.But when contact pairs were GCr15/PDMS, there wasn’t the obvious relationship between adhesionand density. Second, when GCr15/PDMS was used as contact pairs, there was stronger rangeability ofadhesion with different contact conditions, but when PDMS/PDMS was used as contact pairs, therangeability was small. Finally, when there was much water between contact pairs, the PDMS/PDMSpairs adhesion was stronger than GCr15/PDMS. The research believed that the PDMS/PDMS hadbigger deformation which was benefit for groove to drain away water. So the textured PDMS hadbetter adhesion stability when the volume of water changed.The influence of different contact conditions, different kinds of grooves, different contactsurfaces to adhesion was researched in this paper. The mechanism of phenomenon was also disscussed. The conclusion of this research provided some design methods of adhesion control forengineering application of soft materials.