27. June 2022
Xia Peng comes from the most populous country in the world. She grew up in a big city in the east of China, Yancheng. During her master's studies, she tried without much hope to write an e-mail to the leader of her field – Prof. Martin Pumera. Surprisingly, he immediately wrote back and said: we are interested. And after a formal interview, Prof. Pumera invited her to join his team at CEITEC BUT. Together with other colleagues, they are discovering the possibilities of microrobots. And in the meantime, she has already won two competitions.
You came to Brno in February 2021. How did you manage the transition to a foreign city?
Well, at first it was very hard to fit in because it's a completely different environment. China is dotted with huge cities, there is a low chance of seeing the countryside, hills, and beautiful views every day. You'd just have to travel a long way to see that. But here? (starts to smile) I'm just in Brno, in the city, but after work, I go for a walk and I see beautiful panoramas, and landscapes. And I can calm down and feel relaxed. It's just a great feeling. Plus, the people here are very nice.
So would you like to stay here after graduation? Or maybe somewhere else in Europe?
Maybe I'll find some postdoc positions here after I finish my Ph.D. And I really like the life here. But eventually, I will go back to China. It wouldn't be a good choice to stay here for too long, because my family is in China.
You're in prof. Martin Pumera's research group, working on microrobots. What specifically are you researching now?
I’ve finished three projects that are focused on microrobots for water purification. Specifically, I put in about 1 mg of light-powered microrobots mixed in a solution that contains pollutants under light irradiation and waited an hour or two. Then I took out the samples and did some measurements to see if the microrobots had broken down the pollutants in the solution. But this is still in the lab phase. We're not able to go to the river and pour the microrobots in because we wouldn't have control over them at this stage. They'd float away and we wouldn't get any results. And we can take them out of the bottles and reuse them with the magnetic control.
So they could already be used in standing water?
As I said before, it is still in the lab stage, and still a long way toward real-world practical applications. Nitroaromatic explosives, dyes and microplastics are the three types of pollutants that I'm focusing on now. I'm looking for what materials can be used for microrobots and then applying microrobots for breaking down the contaminants. For example, for picric acid degradation, hematite would be a good option, because it exhibits light-powered motion and can be controlled by magnetic fields. Moreover, it can display self-assembly behavior because of the dipolar moment in the structure.
With research on microplastic degradation, you were first in an internal grant competition at the BUT. But you also won the Brno Ph.D. Talent. What was that for?
First, I proposed using light-powered microrobots that can produce ROS to attack, or let’s say, efficiently degrade microplastics in water for the internal grant competition at the VUT. Then, the proposal for Brno Ph.D. Talent was on the removal of bacterial biofilms (communities of microorganisms attached to a surface that defend themselves together and form a "shield" of excreted polysaccharides), which are considered the biggest cause of economic losses in medicine and industry. Therefore, we designed light-driven hematite and silver microrobots; moreover, they had self-assembling and reconfigurable properties for rapid and efficient removal of biofilms from solid surfaces.
What do you consider to be your greatest achievement so far and what would you like to achieve?
Definitely, the Chinese scholarship and winning the Brno Ph.D. Talent. These are my biggest achievements so far. I see myself, maybe in ten years as the head of my own research group somewhere in China. And I would like to be a professor and guide students. I also think that in ten years we will have made a lot of progress in the field of microrobots. By then, we'll definitely be treating industrial wastewater with microrobots. But I also expect progress in biomedicine. I expect that they will already be used to heal wounds faster, etc. I can't imagine much internal use yet, that will be a more complex process.