There are two major variables affecting the properties of a LM: the core and the coating. Traditionally the encapsulated liquid is water, although there are a range of both common (glycerol ) and uncommon (petroleum ) alternatives. The coating provides the largest affect on the mechanical properties of the marble, as it is the coating that interacts with the surface the LM is resting on. Coating parameters that can be modified to impart the desired properties include the composition, grain size, and mix ratio. By varying these, it is possible to adapt a liquid marble to many different situations. Liquid marbles have previously been investigated as fluidic transport devices. They are ideally suited to the transport of microlitre quantities of liquid, due to their non-wetting nature. Recent progress have been made in this area, with LM movement initiated by magnets , electrostatic fields , gravity , lasers and the Marangoni effect all reported. The movement of LMs can be exploited for chemical reactions, by controlling the time and place of reagent mixing. This has been demonstrated both with the coalescing of LMs , and in the controlled destruction of LMs once they arrive at a chosen location .