A lab-on-a-chip device for photonic sensing of single cells

A lab-on-a-chip device for photonic sensing of single cells

Johanna Malmström

Cells are the smallest living units and together they form all living organisms on earth.

The cells are not only the building blocks of all living things, they also possess the most

important information about life. A deeper understanding of these units may reveal

hidden secrets about difficultly cured diseases, memory and learning, among others.

Today’s techniques have problems such as low sensitivity, lethal preparation steps for

the cells and overlaps in result spectra. Microfluidics has shown to be a useful tool that

allows improved dynamic control, high throughput and sensitivity in nL.

The aim with this project is to design a microfluidic system for future integration with

photonic sensors. Three different designs were developed, one design with the aim to

integrate with photonic sensors and two for cell trapping only. Analytical calculations

and numerical simulations were performed to make sure that the designs satisfied the

requirements of single cell trapping. Moreover strength calculations were performed for

the sensor, to make sure it could handle the high pressures.

The fabrication process and the material selection showed proper lithography and

molding. The unevenness on the surface was concluded to primarily come from the

mask and mold, not the fabrication steps itself. The chips enabled liquid flowing through

the channels. However, bubbles appeared in the channels, which could cause

interruption in the flow dynamics and clogging of the system. Further research must be

done to find suitable connectors to the chip, so the bubbles can be removed.