Example fluidic channels for microfluidic devices are disclosed. In examples disclosed herein, an example microfluidic device includes a body having a microfluidic network. The microfluidic network includes a main fluid channel to transport a biological fluid from a first cavity of the microfluidic network to a second cavity of the microfluidic network. An auxiliary fluid channel is in fluid communication with to the main fluid channel. The auxiliary fluid channel has a first end and a second end. The first end is in fluid communication with the main fluid channel and the second end is spaced from the main fluid channel. A fluid actuator is positioned in the auxiliary fluid channel to induce fluid flow in the main fluid channel.