Microfluidic device and methods for using such device

A microfluidic device comprising:

• a lower layer that is electrically conductive and transparent with respect to an incident optical beam,
• an upper layer, comprising
• first portions that are electrically conductive and configured to receive an electrical signal, and
• second portions that are electrically insulating, the first and second portions being adjacent and alternated between them,
• a compartment interposed between the lower layer and the upper layer throughout the extension of the lower layer and of the upper layer and seamlessly extending between the lower layer and the upper layer, the compartment containing a filler medium configured to emit an optical emission beam when lit by an incident optical beam and markers dispersed in the filler medium,
• wherein
• the markers are electrically charged and are adapted to move inside the compartment in all directions in variable amounts according to the intensity of the electrical signal applied to one or more of the first portions, the filler medium being configured to interact with the markers to increase or reduce the intensity of the optical emission beam depending on the local concentration of markers in the compartment, and
• the first portions are spaced between them at a distance between 1 and 100 μm.