Femtosecond Laser-Induced Response Wave Measuring Method for Single Cell Characterization

Once a femtosecond laser impulse is focused in fluids, an acoustic radiation is induced around the focal point. In this research, this acoustic radiation has shown its potential as a phenotyping tool in microfluids. Under the stimulation of such an impulse acoustic radiation, two novel types of response waves (namely, rebound wave and transmitted wave) are found, which are tightly related with the target object within the detection area. To sense both types of waves in microfluidics, an ultra-thin glass sheet (10 μm) -based cantilever is designed at the bottom of the microchannel as an acoustic microsensor, converting acoustic waves into detectable cantilever deformation. To date, we have conducted experiments on 10 μm beads and successfully verified the existence of both types of waves and the function of the proposed microsensor. Besides, the relationship between beads' states and response waves have also been found.