 In 1981, spectators at the playoff game between the Oakland Athletics and New York Yankees did something no other crowd had ever done before. At the direction of Crazy George, the professional cheerleader, they did the wave. Unlike a typical wave, waves like this are metacronal, meaning they're produced by sequential action. Metacronal waves are found almost everywhere, often as a means of transport. They're seen in the tumbling feet of a millipede, in the wriggling hairs on certain bacteria, and now in this nanomaterial created by a team led by researchers from the Re-Kenn Center for Emergent Matter Science. Made of billions of nanosized plates suspended in water, this material forms metacronal waves that its creators say could lead to new types of microscopic engines. The plates are made from titanium oxide, and each carries a densely negative charge. When a magnetic field is applied, the plates align into layers of sheets, stabilized by the like-repels-like forces between the charged plates. Left undisturbed, they can stay that way for hours after the magnetic field is removed. But something interesting happens when you let some air enter the system. Ions, some negative, some positive, start to form. Together, these charged particles decrease the repulsive force between parallel layers of titanium oxide plates. This causes the plates to rotate slightly in position, but not all at once. It starts where the ions first form in the suspension and moves laterally through the layered structure as ions diffuse toward the other end. The result is a propagating wave that gives the aqueous suspension a crinkled appearance. The time the wave takes to travel from end to end depends on the amount of air or other gas that's allowed to diffuse through the suspension, and different wavelengths can be achieved by changing the thickness of the vial holding the suspension. In separate experiments, the Rekin-led team showed that the microscopic metacronal wave could be useful in moving small cargo, as it does in nature. Polymer micro-particles were successfully transported by the propagating wave, like a cleated conveyor belt moves goods down a factory line. The team that created this wave-pull material has high hopes for its potential application. Making big waves from tiny parts could be a useful way of designing new micro-mechanical devices.