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