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