said membrane having formed therein {HEAD ~ a pleated structure} surrounding {TAIL ~ said contact region} and defining a bellows portion for increasing a displacement distance of said contact region of said membrane 
surrounding
said membrane having formed therein { HEAD ~ a pleated structure } surrounding { TAIL ~ said contact region } and defining a bellows portion for increasing a displacement distance of said contact region of said membrane
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH