Background: Aiming to improve the laser-induced forward transfer (LIFT) cell isolation
process, a polydimethylsiloxane (PDMS) layer with micro-hole arrays was employed to improve the
cell separation precision, and a microchip with heater was developed to maintain the working area at
100% humidity and 37°C with the purpose to preserve the viability of the isolated cells.
Methods: A series of experiments were conducted to verify the contributions of the optimization to
LIFT cell isolation process as well as to study the effect of laser pulse energy, laser spot size and the
titanium thickness on cell isolation. With 40µm laser spot size and 40nm thick of titanium, laser energy
threshold for 100% single cell isolating succeed ratio is 7µJ.
Results: According to the staining images and proliferation ratios, the chip did help to improve the cell
availability and the cells can recover from the juries at least a day earlier comparing to the samples
processed without the chip.
Conclusion: With a Lattice Boltzmann model, the cell isolation process is numerically studied and it
turns out that the micro-hole makes the isolation process shift to a micro-syringe injection model
leading to the lower laser energy threshold for cell separation and fewer injuries.