Microfluidic-based in vitro physiological barrier models are capable of simulating crucial environmental factors during barrier formation, including fluid shear and geometric-level cellular cocultures, thus offering enhanced physiological fidelity relative to conventional platforms. However, the sealed structure of microfluidic barrier chips faces challenges in characterizing and monitoring the barrier performance, especially in measuring transendothelial/epithelial electrical resistance (TEER). Here, we developed a microfluidic barrier chip that can be easily adapted to commercial TEER detectors. During the barrier construction phase, continuous perfusion culture was utilized to maintain a constant fluid shear stress
for barrier characterization, commercial resistance meters were employed to measure TEER directly. Using this chip, we successfully constructed an in vitro blood-brain barrier model with a TEER of approximately 220 Ω·cm