High-speed and pinpoint liquid exchange on microfluidic chip using 3d printed double-barreled microprobe with dual pumps

We propose a method to exchange the ultra-small volume of liquid on the microfluidic chip in high-speed by using a 3D printed double-barreled microprobe with dual pumps. The probe tip is designed double-barreled and assembled with two piezoelectric stacks to realize the simultaneous liquid injection and suction. We evaluated the performances of the developed liquid exchange system. The results showed that high-speed and pinpoint liquid exchange can be achieved within 10 ms. The highest flow speed is approximately 18 mm/s. The sensitivity and resolution are 22 pL/v and 0.54 pL respectively. This system will contribute to revealing the detailed cell deformation process under rapid osmolarity change, and characterizing the physiological function of mechanosensitive channels without destroying cells.