Interaction of single biological cell with tandem microbubbles in microfluidics

Coupled oscillation of two laser generated microbubbles (maximum radius = 28 μm) and associated shear stresses are investigated experimentally. Bubble‐bubble interaction in a microchannel of 25 μm height is observed using high‐speed video cameras and μPIV technique. Two liquid microjets moving in opposite directions can be generated when the second bubble is produced at the maximum size of the first one. The interaction of these tandem microbubbles with single cell leads to controllable poration of adjacent cell membrane and dye uptake. μPIV data are compared with cell viability at various bubble‐cell distances and azimuthal orientations. This method provides a new approach for highly selective cell treatment in situ, applicable to targeted microinjection of macromolecules and gene vectors in microfluidics devices. [Work supported in part by NIH.]