Liquid-liquid colliding micro-dispersion and general scaling laws in novel T-junction microdevices

•Two novel T-junction microdevices have been constructed to intensify the colliding micro-dispersion.•The droplet formation frequency is increased by more than 40 times in the novel T-junction microdevice.•The microflow pattern including all three flow regimes in the colliding T-junction microdevice is reported for the first time.•General scaling laws for droplet size under different flow regimes have been established.