KTH designs device to sort cells by elasticity properties
14 July 2014
Researchers at Sweden's KTH The Royal Institute of Technology
have used computational simulations to propose a microfluidic device
that would sort cells according to their elasticity. This could
offer a more reliable alternative for detecting disease biomarkers.
Chemical properties don’t give pathologists the full picture of a
disease. Two cells can have very similar chemical properties, but
different physical properties. Size, shape and elasticity, or
deformability, are important attributes that can be also enable cell
sorting, given the right kind of device.
Dhrubaditya Mitra, Assistant Professor in theoretical physics at
NORDITA, Nordic Institute of Theoretical Physics at KTH and
Stockholm University, offers an example of why elasticity matters.
If you are infected with malaria, the physical nature of your red
blood cells changes, he says. “They become harder. And red blood
cells also become harder as they get older too. These harder red
blood cells are filtered by the spleen which acts like a sieve. The
softer red blood cells can squeeze through the gaps but the harder
Consisting of a duct embedded with a semi-cylindrical obstacle,
and a diffuser, a microfluidic device works in a similar fashion.
Several kinds of microfluidic devices have been fabricated to detect
biophysical markers. But the big challenge has been in designing the
geometries that allow for efficient cell sorting, according to team
leader Luca Brandt, a professor of fluid mechanics at KTH.
Visualization from a numerical simulation of a
past the obstacle through the microfluidic device.
The design was proposed by the researchers at KTH Linne FLOW
Centre and SeRC (Swedish e-Science Centre). Their work draws on
numerical techniques and computational capabilities developed in the
last decade to handle the complexity of microscale flows. The
research was published in the Royal Society of
Chemistry’s journal, Soft Matter .
“A particular novelty of our work is that this design process has
not been done in a laboratory but as a computer simulation,” Brandt
says, comparing their computer simulations to the early stages of
aircraft or vehicle design. “We hope that our work will bring such a
change to design of microfluidic devices, too.”
1. Lailai Zhu, Cecilia Rorai, Dhrubaditya Mitra and Luca Brandt. A
microfluidic device to sort capsules by deformability: A numerical
study. Soft Matter, 2014. DOI: 10.1039/C4SM01097C
published online 20 Jun 2014.