A method is provided. The method includes forming a conductive layer on an
inner surface of a substrate and providing a sacrificial layer over the
conductive layer. The method includes forming a plurality of channels in
the sacrificial layer and plating the sacrificial layer to substantially
fill the plurality of channels with a plating material comprising
conducting material. The method also includes etching the sacrificial
layer to form a conducting structure having fins where conducting
material remains separated by microchannels where the sacrificial layer
is etched.