Rond Table Discussion on: Advanced Control of Active Matter

The last round table of this workshop regarded the topic advanced control of active matter. As organizers of round table, Audrey Nsamela, Chun-Jen Chen, Sandrine Heijnen, Harshith Bachimanchi and Alireza Khoshzaban, we welcomed and introduced our esteemed guests, namely Jérémie Palacci from University of San Diego, Clemens Bechinger from Konstanz University, Frank Cichos from Leipzig University, and Lucio Isa from ETH Zurich.

The round table started out with a clarification on advanced control of active matter. Active matter can be controlled by numerous external stimuli but implementing control on individual particles or artificial entities is what qualifies as advanced control. Currently, the control of active matter is still far from the behavior and control micro-organisms have on that scale; hence a big challenge lies there for us. Jérémie Palacci introduced an interesting research topic where they found a way to regulate the swimming process of E. Coli by light illumination. Here genetic modification was used to control the proton pump involved in the energy transportation process.

Advanced control of active matter can be applied to model systems where the control is lacking, for example biological systems. In a biological system the control over an organism is limited to the external stimuli that are applied and won’t always result in the same reaction. Therefore, using active particles showing predictable and reproducible behaviors when exposed to a stimulus works perfectly to model and to probe different parameters and thus provide a deeper understanding of the system. The fact advanced control of active matter doesn’t have an application outside of modelling systems is something we shouldn’t be ashamed of.

We concluded the meeting by asking every one of our guests what the promising research directions in the advanced control of active matter are. All of them had a different perspective. Starting with  Clemens Bechinger, who was most invested in the further exploration of the applications for model systems. Lucio Isa is mainly looking forward to explore the different materials that we can use to create active material that can subsequently be controlled. Frank Cichos mentioned the importance of looking into new ways to create active particles. So far nature was able to achieve production of active entities with limited waste whereas human production is rather inefficient. Jérémie Palacci pointed out that the current man-made active matter systems are reacting to a strong signal in a well-controlled environment, where nature faces many more factors and still works. It would be interesting to design a system that is resistant to noise.

Round Table Discussion on: Living Active Matter

As part of the experimental training, a second round-table discussion took place yesterday, 18 March 2021. The event centered around a discussion on the topic of « Living Active Matter » and featured four invited guests, all physicists, who have studied different topics and length scales relevant to living systems. The invited panel was composed of Aidan Brown from University of Edinburgh, Salima Rafai who works at CNRS in Grenoble, Eric Clément from PMMH-ESPCI in Paris and Benjamin Friedrich from TU Dresden, and was conducted by six of the students attending the training: Audrey Nsamela, David Bronte, Jérémie Bertrand, Ojus Satish Bagal, Daniela Peréz Guerrero and Dana Hassan, who first introduced each guest and then asked selected questions. From molecules and cells to tissues, organisms and populations, each guest had a particular expertise which made for a wide-ranging and interesting discussion.

A question on the evolutionary role of self-propulsion was met with an answer from Dr Brown, who, as obvious as it may seem, pointed out that organisms become “active” when whatever they need to survive is not in their immediate surroundings and must be found elsewhere. When Dr Rafai suggested that the micro-swimmers she studied were not converting their energy to motion optimally, Dr Brown pointed out that biological systems are optimized only in the sense that they are versatile and can adapt to a large number of situations or physical parameters, which is not something that can be captured by a single experiment. This goes to show that, when given the same set of facts, physicists and biologists will often interpret their observations differently, and that discussions between the two disciplines can be fruitful.

Dr Friedrich pointed out that the inherent complexity of biology was such that you could sometimes make progress by just looking and writing down how the processes unfold. He went on to explain that one of the bigger challenges biologists face is that many of these processes occurr below the resolution limit of the microscopes (the “diffraction barrier”) and can therefore not be observed by regular optical microscopes. Several panelists are excited about the coming of newly-designed, ground-breaking microscopes; devices that would use entangled photons to break the diffraction barrier. These new technologies could help not only the field of biology, but also encourage physicists and chemists to collaborate and create models of previously undiscovered mechanisms at the smaller scales. Deep learning is another tool that was alluded to by Dr Rafai as something to look forward to for image reconstruction.

Overall, we found the discussion very productive and we would like to thank once more the panelists for their insights and willingness to participate!

Audrey Nsamela presents her PhD project at the ActiveMatter online meeting, 10 September 2020

The first online kick off meeting with the consortium (PIs and ESRs) took place last 10th of September. This was an opportunity for all the ESRs to introduce themselves and their project. Audrey Nsamela, ESR at Elvesys and TU Dresden, is giving a short introduction to her project which is at the interface between scientific research and industrial innovation. She is developing a microfluidic platform to study biological microswimmers (i.e. sperm cells) in various flow conditions. Watch the 5 min video to know more !

Audrey Nsamela, ESR at Elvesys and TU Dresden, presents herself and her work on microfluidics and biohybrid active matter.

ActiveMatter PIs+ESRs Online Meeting on 10 September 2020

The ActiveMatter PI+ESRs meeting took place on 10 September 2020. Because of the current travel restrictions and regulations imposed to hinder the spread of the CoViD-19 epidemics, the meeting was held online.

The aim of the meeting was to give an update to all the members on the progress of the ActiveMatter network.

Currently 12 of the 15 Early Stage Researchers (ESRs) have already been recruited and could started their project. During the meeting the ESRs had the opportunity to introduce themselves to the rest of the network and to present their research project.

The presentations of the ESRs have been uploaded on the Youtube channel of the ActiveMatter network and are available online.

Links to the individual presentations:
Liam Ruske, UOXF
Carolina van Baalen, ETH
Audrey Nsamela, ELVESYS
Danne van Roon, FC.ID
Chun-Jen Chen, UKONS
Sandrine Heijnen, UCL
Jesús Manuel Antúnez Dominguez, ELVESYS
David Bronte Ciriza, CNR
Laura Natali, UGOT
Ayten Gülce Bayram, UBIL
Davide Breoni, UDUS
Jérémie Mar Bertrand, EPFL

(Screenshot by Caroline Beck Adiels)

(Screenshot by Giorgio Volpe)

(Screenshot by Giorgio Volpe)

(Screenshot by Agnese Callegari)

(Screenshot by Agnese Callegari)

Audrey Nsamela joins the ActiveMatter ITN

Audrey Nsamela started her training at Elvesys as one of the Early Stage Researchers (ESRs) of the ActiveMatter ITN.

Her work focuses on studying biological and biohybrid microswimmers in microfluidics systems.

She will conduct her research under the supervision of Julia Sepulveda at Elvesys, and co-supervised by Dr. Juliane Simmchen at TU-Dresden.