Concentration gradient generator based on a paper microfluidic device

• Main Author: Siti Kamariah Binte Ahmad
• Other Authors: School of Chemical and Biomedical Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Bioengineering
• Online Access: http://hdl.handle.net/10356/60788
• Institution: Nanyang Technological University

A microfluidic gradient generator manipulates small volumes of reagents, usually in nanolitres or microlitres, through networks of submicron to micrometre-sized channels. The advances in microfabrication technology led to the continuous miniaturization of channel geometries, thereby reducing gradient generating lengths down to micrometer or even nanometre. The miniaturization of channel dimensions directly correlates with the reduction of the time required to transport specific concentration doses to cells, providing physiologically meaningful time scales. The objective of this project is to experimentally design and fabricate a paper-based microfluidic device by a technique called photolithography, after which it will be used as a platform for generating the concentration gradient. A device is proposed here consisting of a paper chip, sandwiched between two layers of PDMS and secured together between plastic mounting plates with screws. Food dyes were used to successfully generate a linear concentration gradient. These coloured solutions underwent a series of dilutions as the fluid streams split and recombined in the microfluidic network. The next step would be to determine if gradients can also be successfully generated using cell culture mediums and various growth factors.