Geckos are able to adhere strongly and release easily from surfaces because the
structurally anisotropic fibers on their toes naturally exhibit force anisotropy based on the
direction of articulation. Here, semicircular fibers, with varying amounts of contact area on
the two faces, are investigated to ascertain whether fiber shape can be used to gain
anisotropy in shear and shear adhesion forces. Testing of 10-μm-diameter
polydimethylsiloxane (PDMS) fibers against a 4-mm-diameter flat glass puck show that …