Polydimethylsiloxane based dry adhesives produced using a replica molding technique.

Dry adhesives have gained considerable interest due to their applications in a wide variety of areas. This study used a replica molding technique to produce micron-sized pillars on the surface of polydimethylsiloxane (PDMS) and investigated their dry adhesion behaviour. Shear adhesion for the produced samples is measured using a tensile testing machine. For this purpose, the sample was initially brought into contact with a glass slide. Following this, the shear adhesion was determined by measuring the shear stress required to slide the sample along the glass slide. Peel adhesion of the samples was measured using an in-house designed and built peel fixture. The force required to peel the sample from the surface of the fixture was measured to determine the peel strength. The shear adhesion and peel tests were also conducted on neat PDMS to determine the effect of surface micropillars on the adhesion performance of the samples. The results show that the shear adhesion strength was 0.12 N cm, while the shear adhesion strength of neat PDMS was determined to be 0.02 N cm. Similarly, the peel strength of the samples was recorded to be 0.15 N cm compared to 0.05 N cm recorded for neat PDMS.