Micro-fluidic chip and reaction system

A micro-fluidic chip, comprising:

• a base substrate;
• a micro-cavity defining layer on the base substrate and defining a plurality of micro-reaction chambers;
• a cover plate on a side of the micro-cavity defining layer away from the base substrate;
• a heating layer between the micro-cavity defining layer and one of the base substrate and the cover plate, and configured to heat the plurality of micro-reaction chambers,
• wherein one of the base substrate and the cover plate away from the heating layer serves as a heat dissipation plate having a first surface facing the heating layer and a second surface away from the heating layer, and an area of the second surface is larger than an area of an orthographic projection of the heating plate on a plane where the heating layer is located;
• wherein the heating layer comprises a plurality of heating electrodes connected in series, and an orthographic projection of the plurality of micro-reaction chambers on the base substrate overlaps an orthographic projection of at least two of the plurality of heating electrodes on the base substrate;
• wherein each of the plurality of heating electrodes extends along a fifth direction, the plurality of heating electrodes are arranged at intervals in a sixth direction, and the fifth direction intersects the sixth direction;
• wherein the plurality of heating electrodes comprises a plurality of first heating electrodes and a plurality of second heating electrodes, and ones of the plurality of second heating electrodes are disposed on both sides of the plurality of first heating electrodes in the sixth direction,
• wherein the plurality of first heating electrodes each comprises a first sub-electrode and a second sub-electrode that are connected, the second sub-electrode is on both sides of the first sub-electrode in the fifth direction, and an orthographic projection of the first sub-electrode on the second surface is in a middle region of the second surface, and
• a resistance of the first sub-electrode per unit length is smaller than a resistance of the second sub-electrode per unit length.