Methods and devices for mixing in a microfluidic system

A method comprising:

• loading an analyte of interest into a microfluidic device, wherein the microfluidic device comprises:
• a flow cell including an inlet port, an outlet port, and at least one flow channel extending between the inlet port and the outlet port, the flow channel to receive the analyte of interest and one or more reagents;
• and
• at least one electrothermal mixing device coupled to the flow cell and positioned proximate to the at least one flow channel, the electrothermal mixing device comprising a passivation layer positioned between the flow channel and an electrode array of the electrothermal mixing device, the electrode array comprising a plurality of electrodes;
• loading a reagent into the flow cell;
• and
• actively mixing the reagent with the analyte of interest in said flow channel via electrothermal mixing by the electrothermal mixing device, wherein the plurality of electrodes comprises a first crescent-shaped electrode, a second crescent-shaped electrode, and a third central electrode,
• wherein the first and second crescent-shaped electrodes each comprise a center portion, a first distal end, and a second distal end,
• wherein the first and second crescent-shaped electrodes are arranged concentrically such that the first distal ends are facing one another and are separated by a first opening and the second distal ends are facing one another and are separated by a second opening, and
• wherein the third central electrode comprises a substantially circular shape having a first wing portion and a second wing portion extending from opposite sides of the substantially circular shape, the third central electrode positioned between the first and second crescent-shaped electrodes such that the first wing portion extends through the first opening and the second wing portion extends through the second opening.

A method comprising:

• loading an analyte of interest into a microfluidic device, wherein the microfluidic device comprises:
• a flow cell including an inlet port, an outlet port, and at least one flow channel extending between the inlet port and the outlet port, the flow channel to receive the analyte of interest and one or more reagents;
• and
• at least one electrothermal mixing device coupled to the flow cell and positioned proximate to the at least one flow channel, the electrothermal mixing device comprising a dielectric material and an electrode array embedded within the dielectric material;
• loading a reagent into the flow cell;
• and
• actively mixing the reagent with the analyte of interest in said flow channel via electrothermal mixing by the electrothermal mixing device.