Microfluidic device and method for manufacturing the same, and method and system for detecting the number of biomolecules

A microfluidic device, comprising:

• a glass substrate;
• a plurality of first metal strips arranged on the glass substrate in a first direction;
• a photoresist extending along the first direction, covering the plurality of first metal strips and exposing a head end and a tail end of each first metal strip;
• a fluid cavity extending in the first direction and formed in the photoresist;
• a plurality of second metal strips formed on the photoresist, wherein the plurality of second metal strips extend over an upper surface of the photoresist, and continuously extend along sidewalls of the photoresist to the glass substrate, to form respective head ends and tail ends, and wherein orthographic projections of the plurality of second metal strips on the glass substrate are along the first direction, the head end of one first metal strip and the tail end of the other first metal strip in any adjacent two first metal strips are electrically coupled with each other through the head end and the tail end of one second metal strip between the two first metal strips, so that the plurality of first metal strips and the plurality of second metal strips form a hollow inductor structure around the fluid cavity, and the hollow inductor structure is provided with a first electrode and a second electrode for an external connection;
• a liquid inlet and a liquid outlet formed at both ends of the photoresist in the first direction, and communicated to the fluid cavity.