{HEAD ~ The volume} of {TAIL ~ sacrificial material} 142 on the surface of the substrate 132 should, therefore, correspond to the volume of the reactant gap 140 
{ HEAD ~ The volume } of { TAIL ~ sacrificial material } 142 on the surface of the substrate 132 should , therefore , correspond to the volume of the reactant gap 140
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH