Further, {HEAD ~ channels} are formed by removing {TAIL ~ portions} of the substrate other than the bodies on the substrate 
are formed by removing
Further , { HEAD ~ channels } are formed by removing { TAIL ~ portions } of the substrate other than the bodies on the substrate
OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH