The hydrophilic or superhydrophilic regions can selective collect {HEAD ~ water} on {TAIL ~ the surface} 
on
The hydrophilic or superhydrophilic regions can selective collect { HEAD ~ water } on { TAIL ~ the surface }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL