For most people the term digital microfluidics doesn’t mean a whole lot. But it’s a technology which could revolutionise lab work completely.
“The idea is that whatever a biochemist normally spends a lot of time doing with pipettes, can be done by a chip instead,” Luca Pezzarossa explains and plays a short video of the technology at work.
The lab on a chip is basically a biochemical lab scaled down to the size of a small portable device. The idea is to make tiny droplets of fluid move around on a chip by activating a sequence of electrodes. Luca Pezzarossa’s job is to make the hardware and software work together to move the microfluidic droplets the right way.
“But one thing that is very common in this field is that the people who do this research are not biochemists, ” he says.
The problem with this is that there are real-world constraints, which makes moving the droplets much harder.
“Two droplets cannot go as close as they do in a simulation, because they would touch and merge. Or from a biological point of view, some droplets might leave behind a contaminating residue. Blood that leaves a trail for example, and so other droplets cannot move where this has moved earlier,” Luca Pezzarossa explains.
This represents a difficult problem. To translate from a high-level protocol that is user-friendly – something which is useful for a biochemist – down to a controlling sequence is very difficult. Especially when the constraints are complex real-world issues, like a droplet leaving a contaminating trail of blood on the chip.
“When I presented these challenges at a DIREC seminar, two algorithm-oriented scientists said: ‘This is very cool from a theoretical point of view. We should apply for a DIREC Explore project.’ And we did,” Luca Pezzarossa says.
Digital Research Centre Denmark (DIREC) supports multidisciplinary research – often with external partners – with the so called Explore projects, which are small agile research projects with the purpose of screening new ideas.
So for most of 2022 he worked with two fellow assistant professors, Eva Rotenberg from DTU Compute and Lene Monrad Favrholdt from University of Southern Denmark, on developing algorithms that could do this scheduling and routing on applied cyber-physical systems – while DTU research assistant Kasper Skov Johansen, who is now a PhD student at DTU, did most of the practical work.