Femtosecond laser manipulation techniques for individual patterning of biological micro-object

Several kinds of manipulation of biological cells were performed utilizing regeneratively amplified femtosecond laser system. When single-shot pulse of an amplified Ti: Sapphire femtosecond laser pulse is focused on a culture medium, Shockwave and cavitation bubble are generated with little heating. An impulsive force resulting in these phenomena was applied to pttern specific cells form a culture substrate. Furthermore, laser trapping of cells was realized using high-repetition rate pulses from the laser oscillator. Although the cell was trapped stably when the laser power was less than 100 mW, the cell was burst above the threshold laser power. The bursting would be due to heating inside cell, on which the laser was focused and multiphoton absorption was induced. On the bases of these results, we propose a new methodology to pattern biological cells, which is speedy and flexible when compared with previous micropatterning methods.