The apparatus 1, further comprising an amplitude detector that detects {HEAD ~ an amplitude} of the torsional motion of {TAIL ~ the cantilever} 
The apparatus 1 , further comprising an amplitude detector that detects { HEAD ~ an amplitude } of the torsional motion of { TAIL ~ the cantilever }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL