The present invention provides a method and apparatus for dispensing a small volume of a selected liquid, such as a biological sample or reagent, onto a substrate. An input signal, which may be analog or digital, is connected to a modulator. TBCs exhibiting low thermal conductivity are applied to combustor panel areas that are exposed to hotter temperatures and TBCs exhibiting higher thermal conductivity are applied to areas that are exposed to lower temperatures. The configuration directives can be organized into policies.