Micro Groove for Trapping of Flowing Cell

Micro grooves have been designed to trap a biological cell, which flows through a micro channel in vitro. Each micro groove of a rectangular shape (0.002 mm depth, 0.025 mm width and 0.2 mm length) has been fabricated on the surface of the polydimethylsiloxane (PDMS) disk with the photolithography technique. Variation has been made on the angle between the longitudinal direction of the groove and the flow direction: zero, 0.79, or 1.57 rad. A rectangular flow channel (0.1 mm depth x 5 mm width x 30 mm length) has been constructed with a silicone film of 0.1 mm thick, which has been sandwiched by two transparent PDMS disks. Two types of biological cells were used in the test alternatively: C2C12 (mouse myoblast cell line originated with cross-striated muscle of C3H mouse), or 3T3-L1 (mouse fat precursor cells). A constant flow (2.8 x 10-11 m3/s) of a suspension of cells was introduced with a syringe pump. The behavior of cells moving over the micro grooves was observed with an inverted phase contrast microscope. The results show that the cell is trapped with the micro grooves under the wall shear rate of 3 s-1 for a few seconds and that the trapped interval depends on the kind of cells.