Figure 1.

System setup consists of a pipette tip, a microchip on a glass slide, a coiled PU tube for collecting media, an osmotic pump unit, and PEG solution in a Petri dish. (a) The main channel has dimensions of 200 μm in height, 5 mm in width, and 20 mm in length. Culture media in the pipette tip slowly flow into the main channel of the chip where ECs are cultured. (b) PU tube primed with DI water connects the microchannel and the osmotic pump unit. A small air bubble is inserted intentionally to prevent mixing of collected media and DI water. (c) Osmosis occurs due to the concentration difference between PEG solution and the DI water in the osmotic pump unit through the water-permeable cellophane membrane.