A laser driven optofluidic device for high-speed and precise volume-controlled droplet generation on demand

We report on an ultra-fast, pulse laser-driven droplet generation (PLDG) mechanism that enables on-demand droplet generation up to 10,000 droplets/sec, and continuous tuning of injected droplet volume ranging from 1pL to 150pL with precise volume control (0.26% volume variation) in a microfluidic device. On-demand droplet generation in PLDG is realized by focusing intense laser pulses into water to induce rapid bubble expansion and perturbing an oil-water interface for droplet formation. Device reliability testing of continuous excitation for 3.6 million laser pulsing cycles is also achieved without any damages.