Cell function is largely controlled by an intricate web of macromolecular interactions called signaling networks. It is
known that the type and the intensity (concentration) of stimulus affect cell behavior. However, the temporal aspect of
the stimulus is not yet fully understood. Moreover, the process of distinguishing between two stimuli by a cell is still not
clear. A microfluidic device enables the delivery of a precise and exact stimulus to the cell due to the laminar flow
established inside its micro-channel. The slow stream delivers a constant stimulus which is adjustable according to the
experiment set up. Moreover, with controllable inputs, microfluidic facilitates the stimuli delivery according to a certain
pattern with adjustable amplitude, frequency and phase.
Several designs of PDMS microfluidic device has been produced in this project via photolithography and soft
lithography processes. To characterize the microfluidic performance, two experiments has been conducted. First, by
comparing the fluorescence intensity and the lifetime of fluorescein in the present of KI, mixing extent between two
inputs was observed using Frequency Lifetime Imaging Microscopy (FLIM). Furthermore, the input-output relationship
of fluorescein concentration delivered was also drawn to characterize the amplitude, frequency and phase of the inputs.
Second experiment involved the cell culturing inside microfluidic. Using NG108-15 cells, proliferation and
differentiation were observed based on the cell number and cell physiological changes.
Our results demonstrate that hurdle design gives 86% mixing of fluorescein and buffer. Relationship between inputoutput
fluorescein concentrations delivered has also been demonstrated and cells were successfully cultured inside the