The microchannels for liquid transport are formed by first
electroplating the bottom copper layer from 18 to 100 μm and
then using photolithography and wet etching to define 200-μm
wide by 80-μmdeep pillars, as seen in Fig. 4. Pillars are chosen,
rather than channels, to allow liquid to return to the evaporator
from any direction and achieve uniform liquid distribution in
the evaporating area.