News

David was awarded the best Poster Prize at NanoPlasm 2022

David during the poster session at Cetraro. (Photos provided by D. Bronte Ciriza)
During the conference NanoPlasm 2022, David was awarded the best Poster Prize, sponsored by Nanophotonics Journal – De Gruyter. The poster session was full of interesting discussions and ideas with curious researchers. After the official poster sesion we organized a small presentation taking advantage of the beautiful location. Is the future of poster presentations in locations like this?

Spontaneous, self-organized poster session at the beach. (Photos provided by D. Bronte Ciriza)

David participated in NanoPlasm 2022, 13-17 June, Cetraro, Italy

David during his elevator pitch talk at NanoPlasm 2022. (Photos provided by D. Bronte Ciriza)
Between the 13th and the 17th of June David participated in NanoPlasm 2022, which took place in Cetraro, Calabria, Italy. The conference was focused on the rapidly growing fields of Plasmonics and Nano-Photonics, which are opening new frontiers in nanoscience and advanced technologies via novel cross-disciplinary research activities. During this conference David presented 2 posters (titles: “Machine learning enhanced calculations of optical forces in the geometrical optics approximation” and “Elongated active particles in speckle fields“) and an elevator pitch talk, introducing his work on machine learning for optical forces calculations and his recent work on elongated active particles in speckle fields.

David participated in the 2022 Young Minds Leadership meeting

David and Fabio with the poster presenting the activities of the Messina chapter. (Photos provided by D. Bronte Ciriza)
Between the 2nd and the 4th of June, David was invited to the YM Leadership meeting in Paris to present the outreach activities carried out by the student chapter in Messina. After three years of virtual engagement the meeting brought together almost 50 YM delegates from 20 different countries as well as many interested students and young researchers from outside of the YM network, making it a great success.

Beyond the programme of the LM the co-location with the EPS Forum, allowed the participants to learn about industrial opportunities and to attend lectures from world-class researchers, including 3 Nobel Laureates. Scientific outreach, cultural exchange, and peaceful international collaboration are more important than ever. Bringing young scientists together and equipping them with tools and skills is a great way of fostering these aspects.

Liam Ruske gives a talk at the CECAM Computational methods and tools for complex suspensions workshop, 23-27 May 2022, Bilbao, Spain

Between the 23rd and the 27th of May 2022 Liam participated in the CECAM workshop on Computational methods and tools for complex suspensions to present some of his work. In his talk titled “Modelling biological matter as active nematic fluids” he highlighted how numerical simulations of active fluids can be used to study the self-organization of three-dimensional tissues in a variety of biological systems, where a continuous influx of energy on a single-cell level drives striking collective behaviour at the tissue scale.

Laura Natali and David Bronte Ciriza presented an effective communication activity in Lisbon

Laura Natali and David Bronte Ciriza during the presentation on the fundamentals of effective communication.(Photo by Alireza Khoshzaban.)
During the ActiveMatter meeting in Lisbon, Laura Natali and David Bronte Ciriza proposed a two hours activity on the fundamentals of effective communication. The activity was structured  in an interactive way, and it began with a open discussion about the importance of communication, especially in science.

Then, the ESRs briefly described their research in a popular science style, so addressed to a broader public. The first hour concluded with a presentation about rules to keep in mind while communicating both in oral and written form.

Afterwards, a few examples among the written texts were selected and discussed with all the participants. The aim was to exchange feedback and suggestions on how to make the communication more effective. The feedback was the inspiration for everyone to review their communication example, and the final versions are being uploaded on the official twitter account @ActiveMatterITN.

Collective response of microrobotic swarms to external threats published in New Journal of Physics

A swarm of microrobots, consist of active Janus colloids (middle right, not to scale), can form stationary swirl (upper) and respond to a threat as a whole (lower) when each individual follows cohesive “social rules”. Such rules are inspired by living animals and enable the swarm collective benefits, e.g. enhanced robustness of the response. (Image by C-J Chen.)
Collective response of microrobotic swarms to external threats

Chun-Jen Chen and Clemens Bechinger
New J. Phys. 24 033001 (2022)
doi: 10.1088/1367-2630/ac5374
repository: KOPS:56911

Many animal species organize within groups to achieve advantages compared to being isolated. Such advantages can be found e.g. in collective responses which are less prone to individual failures or noise and thus provide better group performance. Inspired by social animals, here we demonstrate with a swarm of microrobots made from programmable active colloidal particles (APs) that their escape from a hazardous area can originate from a cooperative group formation. As a consequence, the escape efficiency remains almost unchanged even when half of the APs are not responding to the threat. Our results not only confirm that incomplete or missing individual information in robotic swarms can be compensated by other group members but also suggest strategies to increase the responsiveness and fault-tolerance of robotic swarms when performing tasks in complex environments.

Press release at Universität Konstanz website:
How animal swarms respond to threats: With the help of microrobots, Konstanz physicists decode how swarms of animals respond effectively to danger [in English]

Brownian particles driven by spatially periodic noise published in EPJE

Brownian particles driven by spatially periodic noise
Davide Breoni, Ralf Blossey, Hartmut Löwen
The European Physical Journal E 45, 18 (2022)
arXiv: 2111.10220
DOI:10.1140/epje/s10189-022-00176-4

We discuss the dynamics of a Brownian particle under the influence of a spatially periodic noise strength in one dimension using analytical theory and computer simulations. In the absence of a deterministic force, the Langevin equation can be integrated formally exactly. We determine the short- and long-time behaviour of the mean displacement (MD) and mean-squared displacement (MSD). In particular we find a very slow dynamics for the mean displacement, scaling as t^(-1/2) with time t. Placed under an additional external periodic force near the critical tilt value we compute the stationary current obtained from the corresponding Fokker-Planck equation and identify an essential singularity if the minimum of the noise strength is zero. Finally, in order to further elucidate the effect of the random periodic driving on the diffusion process, we introduce a phase factor in the spatial noise with respect to the external periodic force and identify the value of the phase shift for which the random force exerts its strongest effect on the long-time drift velocity and diffusion coefficient.

A platform for stop flow gradient generation to investigate chemotaxis published in Angewandte Chemie

A controlled gradient of hydrogen peroxide is generated in a microfluidic chip where a precise pressure retroactive loop prevents any external flow to interfere with the chemotaxis response of catalytic microswimmers. (Image by A. Nsamela.)
A platform for stop flow gradient generation to investigate chemotaxis
Z. Xiao, A. Nsamela, B. Garlan, and J. Simmchen
Angew. Chemie Int. Ed., Feb. 2022
chemRxiv: 10.26434/chemrxiv-2021-sxqm1
DOI: 10.1002/anie.202117768

The ability of artificial microswimmers to respond to external stimuli and the mechanistical details of their origins belong to the most disputed challenges in interdisciplinary science. Therein, the creation of chemical gradients is technically challenging, because they quickly level out due to diffusion. Inspired by pivotal stopped ow experiments in chemical kinetics, we show that microfluidics gradient generation combined with a pressure feedback loop for precisely controlling the stop of the flows, can enable us to study mechanistical details of chemotaxis of artificial Janus micromotors, based on a catalytic reaction. We find that these copper Janus particles display a chemotactic motion along the concentration gradient in both, positive and negative direction and we demonstrate the mechanical reaction of the particles to unbalanced drag forces, explaining this behaviour.

David presented an oral contribution at PHOTOPTICS 2022

Snapshot of the motion of an ellipsoid in a double beam optical trap. (Image by D. Bronte Ciriza)
Optical systems are ubiquitous in modern society, with an ever-increasing number of applications covering medical sciences, spatial exploration, information processing and industry, to name but a few examples. In this context, David presented his work on machine learning enhanced optical forces calculations at PHOTOPTICS 2022 between the 10th and the 11th of February. The conference took place online and it was the perfect opportunity to learn from other scientists and discuss the relevance of optics for the study of active matter systems.

Jesús Domínguez presents a poster at NanoBioTech in Montreux, Switzerland, 15-17 November 2021

The ESR Jesus Manuel Antunez Dominguez presenting his poster at the NanoBioTech Conference. Image by J. Domínguez.
Jesús Domínguez attended the NanoBioTech Conference in Montreaux, Switzerland, 15-17th November 2021.
He presented the poster “A microfluidic platform for the study of bacterial biofilms” showing his advances in the development of a droplet-based microfluidic platform for in situ observation of bacterial behavior and biofilms.

The NanoBioTech Conference brings together international researchers in the fields of Micro- and Nanotechnology and its applications in Biology and Medicine.

Apart from the featured talks and presentations on related topics and techniques of interest, Jesus benefited from the direct contact with international researchers, that promoted an exchange of ideas and opens the door for possible future collaborations.