In the former case, for example, a groove serving as a channel is formed on {HEAD ~ the surface} of {TAIL ~ the substrate} 
of
In the former case , for example , a groove serving as a channel is formed on { HEAD ~ the surface } of { TAIL ~ the substrate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL