▁F AC S ▁to ▁identify ▁target ▁cells . ▁The ▁flow ▁path ▁is ▁changed ▁in ▁order ▁to ▁direct ▁cells ▁of ▁particular ▁interest ▁to ▁an ▁out let ▁that ▁tra ps ▁the ▁cells ▁for ▁further ▁experiment ation . ▁There ▁exists ▁different ▁methods ▁of ▁actu ation ▁that ▁have ▁been ▁shown ▁to ▁alter ▁the ▁flow ▁characteristics ▁and ▁maintain ▁cell ▁vi ability ▁after ▁sorting ▁and ▁these ▁include : ▁pie zo elect ric ▁actu ation , ▁die lect roph ores is ▁of ▁dro ple ts , ▁optical ▁manip ulation , ▁and ▁surface ▁ac oust ic ▁wave ▁( SA W ) ▁def lection . ▁These ▁methods ▁are ▁usually ▁more ▁cost ly ▁due ▁to ▁special ized ▁equipment ▁or ▁complex ▁components ▁that ▁require ▁control ▁for ▁sorting ▁and ▁data ▁ac quisition . ▁ ▁Pass ive ▁ ▁This ▁method ▁of ▁cell ▁sorting ▁uses ▁the ▁behavior ▁of ▁the ▁fluid ▁itself ▁within ▁the ▁micro ch annels ▁to ▁alter ▁and ▁separate ▁cells ▁based ▁on ▁size ▁and ▁morph ology . ▁The ▁fluid ▁in ▁a ▁col lo idal ▁solution ▁will ▁be ▁subject ▁to ▁a ▁velocity ▁profile ▁due ▁to ▁the ▁interactions ▁of ▁the ▁fluid ▁with ▁the ▁walls ▁of ▁the ▁channel ▁while ▁the ▁cells ▁in ▁the ▁solution ▁are ▁subject ▁to ▁various ▁drag ▁and ▁in ert ial ▁forces ▁that ▁are ▁dependent ▁on ▁the ▁size ▁of ▁the ▁cell ▁and ▁balance ▁accordingly ▁at ▁different ▁locations ▁along ▁the ▁velocity ▁profile . ▁In ▁cur ved ▁micro fl uid ic ▁channels , ▁v ort ices ▁are ▁formed ▁due ▁to ▁the ▁Dean ▁force ▁which ▁locate ▁different ▁s ized ▁particles ▁in ▁different ▁cross ▁section al ▁locations ▁due ▁to ▁the ▁Reyn