• Generally, integrated microfluidic device process fluids of extremely small size components and the sample fluid analyzed inside the device by moving the fluid one direction to other direction.
• The fluid flow in the micro-channel arises from an applied pressure difference or electro osmosis. And in pressure driven flows, the pressure at inlet is higher than that the outlet.
• The residence of time of the sample is important, and there is high demand of development of microfluidic device in increase the residence time.
• Hence, the present patent provides the solution to address the above issues.

Present invention describes about a microfluidic device to increase the residence time in the lab-on-chip devices and reuse expensive chemicals and raw materials.

• The substrate is adapted to receive an electric field in the recycle channel to reverse the flow of the fluid thereby increasing the residence time of the fluid.
• The recycle flow is initiated once the applied electric field reaches beyond its critical value.
• Present invention talks about a microfluidic device and a method of recycling fluid in micro-fluidic device.

The microfluidic device comprises a few elements mentioned hereinbelow:

1. A substrate including two parallel channels for fluid communication, wherein first channel with an inlet to receive a fluid and an outlet to exit the fluid.
2. A pump coupled to the inlet of the first channel to create pressure difference between inlet and exit and determine direction of the fluid flow in the channels.
3. The second channel is adapted to receive an electric field by means of electrodes to reverse the fluid flow and increase residence time.

The method of recycling fluid in micro-fluidic device comprising the steps of

a) receiving sample fluid in the first channel.

b) applying an electric field sufficient to reverse the fluid flow in the second channel.