The apparatus 1, further comprising a switching element operable to selectively connect the surface region to a source of {HEAD ~ potential} that is at {TAIL ~ a reset level} 
is at
The apparatus 1 , further comprising a switching element operable to selectively connect the surface region to a source of { HEAD ~ potential } that is at { TAIL ~ a reset level }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL