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