I've been highly interested in the van der Waals setae adhesive since it was discovered how geckos can stick to walls about three years ago. I have a few questions about it though and I haven't found the answers. What does "directional adhesive" mean? Do geckos have to hang from their toes or can their toes also be below them and they push up from them? Basically I want to find out how geckos and eventually machines will be able to hold themselves on walls, buildings, cliffs etc. Could they stand off the wall without the adhesive pealing off or will they have to keep their bodies close to the surface being climbed to keep gravity from peeling them off like a long shaft of tungsten duct taped to the wall? Or does this even happen? I've never had a long tungsten rod to test it out with. Here's a link for the people not in the know to get up to speed. Autumn Gecko Lab Thank you in advance for the help.