Many new devices need to move nano- and micro-scale quantities of liquid from an external source to a sensor. Technology has been developed to transport very tiny volumes of liquids without the need for electricity or other external energy source. The device is especially useful when surface forces overcome the flow in channels, or when high-precision control of rates and volume are needed. The surfaceenergy gradient coating technology produces enhanced capillary action in nano-scale plumbing to move and mix liquids, and to introduce chemicals or biologics for reactions.The invention allows for directed, passive movement of liquid along a surface or through channels and tubes. In addition, the device eliminates liquid hold-up and reduces required sample volumes over those needed for prior wicking- type designs. Fluid within the gradient region can also be constrained without the use of walls or channels.