Microfluidic chip and device

A microfluidic device, comprising:

• a microfluidic chip, comprising:
• a first sorting assembly, including a first sorting chamber, a first sample inlet channel, and two first guiding channels, wherein the first sample inlet channel and the two first guiding channels are converged at a first side of the first sorting chamber, and the first sample inlet channel is positioned between the two first guiding channels;
• a first sample outlet channel, having an inlet end reaching a second side of the first sorting chamber and a distal end being distant from the inlet end;
• a pouring channel, branched from the first sample outlet channel at a first joint of the first sample outlet channel;
• a collection channel, branched from the first sample outlet channel at a second joint of the first sample outlet channel and including an ejection hole connected to a droplet ejection device to dispense a single droplet;
• and
• a first waste channel, the first sorting chamber bifurcating into the first waste channel and the first sample outlet channel at the second side,
• wherein the first sample outlet channel consists of an entrance section positioned between the inlet end of the first sample outlet and the first joint, a buffer section positioned between the first joint and the second joint, and a drain section positioned between the second joint and the distal end of the first sample outlet;
• a pouring element, connected to the pouring channel;
• a flow adjustment element, connected to the distal end of the first sample outlet channel, when actuated, a flow resistance to the fluid flow in the drain section being lower than a flow resistance to the fluid flow in the collection channel;
• and
• a processor, configured to control the pouring element to pour a guiding fluid into the pouring channel entering the buffer section of the first sample outlet channel and control the flow adjustment element to adjust a flow resistance of the drain section of the first sample outlet channel.