Empty space 8 above the bead layer 4, 5 and 6 may facilitate {HEAD ~ specimen flow} and allow {TAIL ~ mechanical detachment} depicted in FIG 5 
allow
Empty space 8 above the bead layer 4 , 5 and 6 may facilitate { HEAD ~ specimen flow } and allow { TAIL ~ mechanical detachment } depicted in FIG 5
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH