A device and method for propelling objects using periodic or harmonic
vibrations is described. The device comprises a flexible substrate or
surface and a source of vibrational energy that is applied to the
substrate or surface. Specific embodiments include a device which can
move along a flat surface, which can climb a smooth vertical or slanted
wall, which can move along a ceiling while suspended upside down, which
can climb up a smooth hollow tube, or which can move through liquids.