Fig. 3
From: Technologies for circulating tumor cell separation from whole blood
Different CTC membrane microfilters where a an FMSA contains highly porous and flexible micro spring structures in a single layer [32] and b shows a separable bilayer structure where capture is achieved by a gap between the top and bottom porous membranes with 8-μm-diameter holes arranged hexagonally on the bottom layer and larger holes with a diameter of 40 μm on the top layer [33]