Playing with actuators in microfluidic systems

In the labs-on-a-chip of the future, flows will be driven though mazes of microchannels and it will be crucial to integrate actuators achieving flow control ; having actuation available on-chip thus seems a condition for producing large palettes of functionnalities, in a way that could bear comparison with microelectronic devices. In the present paper, we work with PDMS microfluidic systems, and the actuators are made by using multi layer soft technology [1,2]. Thus far, these actuators have mostly been used for producing valving and pumping. Here we describe different usages for these actuators : in particular, we use them for perturbing flow patterns rather than just stopping or driving fluids. This gives rise to interesting functionalities, such as mixing, extracting, building concentration gradients and controlling droplet sizes and emission frequencies.