CROSS-REFERENCE TO RELATED APPLICATION

This application is the U.S. national phase of PCT Application No. PCT/CN2019/079845 filed on Mar. 27, 2019, which claims priority to Chinese Patent Application No. 201810540679.1 filed on May. 30, 2018, which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to the field of sensing and biological detection technologies, in particular to a microfluidic device, a driving method and a microfluidic detection system.

BACKGROUND

With increasing requirements for detection in the field of biomedicine, higher requirements are put forward for microfluidic chips in microfluidic detection systems in accurate measurement and regulation of droplets.

SUMMARY

One embodiment of the present disclosure provides a microfluidic device including: a substrate; two first optical waveguides disposed opposite each other on the substrate with an accommodating chamber defined between the two first optical waveguides; and a plurality of optical detection structures in the accommodating chamber. The first optical waveguide has a refractive index greater than a refractive index of a medium surrounding the first optical waveguide, thereby enabling light rays incident into an end of the first optical waveguide to propagate towards another end of the first optical waveguide in a total reflection mode.

Optionally, a plurality of grooves is defined in a surface of the substrate; the plurality of optical detection structures are disposed in the plurality of grooves in a one-to-one manner.

Optionally, the microfluidic device further includes a plurality of light coupling structures which are disposed in the plurality of grooves and corresponding to the plurality of optical detection structures in a one-to-one manner; and the optical detection structure is located at one side of the light coupling structure corresponding to the optical detection structure distal to the first optical waveguide.

Optionally, the light coupling structure is a grating or scattering particles in the groove.

Optionally, the accommodating chamber is a channel defined by the two first optical waveguides on the substrate; the end of the first optical waveguide is a liquid inlet region of the channel; and the another end of the first optical waveguide is a liquid outlet region of the channel.

Optionally, the two first optical waveguides each are a strip-shaped structure and are parallel to each other.

Optionally, the channel has a bottom; and orthographic projections of the plurality of optical detection structures onto a plane where the bottom is located, are arranged along a center line of the bottom.

Optionally, the microfluidic device further includes a light coupling-in structure; and the light coupling-in structure is disposed at the end of the first optical waveguide and configured to couple incident light rays into the first optical waveguide.

Optionally, the light coupling-in structure is a scattering hole or a grating disposed in the end of the first optical waveguide.

Optionally, the microfluidic device further includes another substrate disposed opposite to the substrate, the two first optical waveguides are between the substrate and the another substrate; and a size of the another substrate is smaller than a size of the substrate with the and the another end of the first optical waveguide being exposed out.

Optionally, a first electrode is disposed on a surface of the substrate, and a second electrode is disposed on a surface of the another substrate. The first electrode includes a plurality of sub-electrodes, the plurality of sub-electrodes are corresponding to positions of the plurality of optical detection structures in a one-to-one manner; and the sub-electrode is located between the optical detection structure corresponding to the sub-electrode and the light coupling structure corresponding to the optical detection structure which is corresponding to the sub-electrode.

Optionally, the microfluidic device further includes two second optical waveguides disposed between the two first optical waveguides, one of the two second optical waveguides is located at one end of the channel and the other of the two second optical waveguides is located at the other end of the channel; the two second optical waveguides are integrally formed with the first optical waveguides thereby forming the accommodating chamber.

One embodiment of the present disclosure provides a microfluidic detection system including: the above microfluidic device; and a calculation circuit coupled to the optical detection structures of the microfluidic device and configured to calculate a liquid parameter of liquid in the accommodating chamber according to light rays acquired by the optical detection structures.

Optionally, the microfluidic detection system further includes a light source disposed at an end of the first optical waveguide of the microfluidic device.

One embodiment of the present disclosure provides a method for driving the above microfluidic device including: driving liquid to flow into the accommodating chamber; controlling light rays to enter the first optical waveguide at an end of the first optical waveguide; wherein the light rays propagate towards another end of the first optical waveguide in a total reflection mode; when the light rays travel to a position corresponding to the liquid, at least some of the light rays emit from the first optical waveguide and are incident into the liquid; and detecting light rays emitted from the liquid.

Optionally, the microfluidic device further includes another substrate disposed opposite to the substrate; a first electrode is disposed on a surface of the substrate, and a second electrode is disposed on a surface of the another substrate; the method includes: generating a driving electric field for controlling positions of the liquid in the accommodating chamber by applying voltages to the first electrode and the second electrode.

Optionally, the method further includes controlling positions of the liquid in the accommodating chamber by using a microfluidic pump.

