News

Talk by Chun-Jen Chen at Institute of Physics, Academia Sinica (Taiwan), 21 January 2022

This talk focused on the social collective response of a group of active particles to a threat, demonstrated in the figure above (the threat appeared at t = 0s). (Image by C-J Chen.)
On the 21st of January 2022, Chun-Jen gave a talk at Institute of Physics, Academia Sinica (Taipei, Taiwan) with title “Collective response of microrobotic swarms to external threats”. Chun-Jen shared and discussed about his most recent scientific work, which involves active Janus colloids and animal collective behaviours, with researchers and students of several fields, including biophysics, soft-matter, and surface/nano science.

David’s secondment at UCL

David (right) discussing the results with Phil Jones (left). (Photos provided by D. Bronte Ciriza)
Between the 11th of the January and the 14th of April David visited UCL to work together with Giorgio Volpe and Phil Jones. During this time in London he studied elongated active particles in complex optical fields, finding some interesting properties that still need to be further understood. Getting to know other people working with soft and active matter gave rise to new ideas and inspiration. More to come!

David visits the Soft Materials and Interfaces lab at ETH Zurich

Carolina (left) and David (right) in the micro 3D printing room. (Image by D. Bronte Ciriza.)
From the 11th to the 19th of December 2021, David Bronte Ciriza visited the Soft Materials and Interfaces lab at ETH Zurich. During this visit, David learnt different techniques to fabricate elongated microparticles, and together with  Carolina van Baalen produced the ones that will be tested under different optical landscapes in David’s secondment in UCL London. This visit has also served as an opportunity to meet other early stage researchers at ETH Zurich working in related topics, allowing to discuss different ideas in the fields of microfabrication, optical tweezers, and active matter.

Raman tweezers for tire and road wear micro- and nanoparticles analysis published in Environmental Science: Nano

Raman Tweezers are used to detect tires and road wear particles in water. We analyze samples collected from a brake test platform, highlighting the presence of car tires and brake particles debris with sub-micrometric dimensions. (Featuring work from Dr Pietro G. Gucciardi, Prof Giovanni Volpe, and Dr Fabienne Lagarde).
Raman tweezers for tire and road wear micro- and nanoparticles analysis

R. GillibertA. MagazzùA. CallegariD. Bronte-CirizaA. FotiM. G. DonatoO. M. MaragòG. VolpeM. L. de La ChapelleF. Lagarde and P. G. Gucciardi.

Environmental Science: Nano (2022) doi: 10.1039/D1EN00553G

Abstract:

Tire and road wear particles (TRWP) are non-exhaust particulate matter generated by road transport means during the mechanical abrasion of tires, brakes and roads. TRWP accumulate on the roadsides and are transported into the aquatic ecosystem during stormwater runoffs. Due to their size (sub-millimetric) and rubber content (elastomers), TRWP are considered microplastics (MPs). While the amount of the MPs polluting the water ecosystem with sizes from ∼5 μm to more than 100 μm is known, the fraction of smaller particles is unknown due to the technological gap in the detection and analysis of <5 μm MPs. Here we show that Raman tweezers, a combination of optical tweezers and Raman spectroscopy, can be used to trap and chemically analyze individual TRWPs in a liquid environment, down to the sub-micrometric scale. Using tire particles mechanically grinded from aged car tires in water solutions, we show that it is possible to optically trap individual sub-micron particles, in a so-called 2D trapping configuration, and acquire their Raman spectrum in few tens of seconds. The analysis is then extended to samples collected from a brake test platform, where we highlight the presence of sub-micrometric agglomerates of rubber and brake debris, thanks to the presence of additional spectral features other than carbon. Our results show the potential of Raman tweezers in environmental pollution analysis and highlight the formation of nanosized TRWP during wear.

Raman Tweezers for Tire and Road Wear Micro- and Nanoparticles Analysis published in Environmental Science: Nano

Optical beam focused into the liquid: the tire particles are pushed away from the laser focus.

Raman Tweezers for Tire and Road Wear Micro- and Nanoparticles Analysis
Pietro Giuseppe Gucciardi, Gillibert Raymond, Alessandro Magazzù, Agnese Callegari, David Bronte Ciriza, Foti Antonino, Maria Grazia Donato, Onofrio M. Maragò, Giovanni Volpe, Marc Lamy de La Chapelle & Fabienne Lagarde
Environmental Science: Nano 9, 145 – 161 (2022)
ChemRxiv: https://doi.org/10.33774/chemrxiv-2021-h59n1
doi: https://doi.org/10.1039/D1EN00553G

Tire and Road Wear Particles (TRWP) are non-exhaust particulate matter generated by road transport means during the mechanical abrasion of tires, brakes and roads. TRWP accumulate on the roadsides and are transported into the aquatic ecosystem during stormwater runoffs. Due to their size (sub-millimetric) and rubber content (elastomers), TRWP are considered microplastics (MPs). While the amount of the MPs polluting the water ecosystem with sizes from ~ 5 μm to more than 100 μm is known, the fraction of smaller particles is unknown due to the technological gap in the detection and analysis of < 5 μm MPs. Here we show that Raman Tweezers, a combination of optical tweezers and Raman spectroscopy, can be used to trap and chemically analyze individual TWRPs in a liquid environment, down to the sub-micrometric scale. Using tire particles mechanically grinded from aged car tires in water solutions, we show that it is possible to optically trap individual sub-micron particles, in a so-called 2D trapping configuration, and acquire their Raman spectrum in few tens of seconds. The analysis is then extended to samples collected from a brake test platform, where we highlight the presence of sub-micrometric agglomerates of rubber and brake debris, thanks to the presence of additional spectral features other than carbon. Our results show the potential of Raman Tweezers in environmental pollution analysis and highlight the formation of nanosized TRWP during wear.

Featured in:
University of Gothenburg > News and Events: New technology enables the detection of microplastics from road wear
Phys.org > News > Nanotechnology:New technology enables the detection of microplastics from road wear
Nonsologreen > Green: Le Raman-tweezers per la guerra alle nanoplastiche che inquinano fiumi e mari

Laura Natali and Jesús Domínguez participate in the Ämnets dag at the University of Gothenburg

Presentation of Laura Natali and Jesús Domínguez at the Ämnets dag. Image by L. Natali and J. Domínguez.
On Tuesday 2 November 2021 the Ämnets dag took place at the university of Gothenburg.

At the Ämnets dag, different high-school teachers of physics and science were given the chance to attend different workshops dealing with lines of research inside the Physics department. Laura Natali and Jesus Manuel Antunez Dominguez joined the initiative and prepared an introductory class to simulations modelling active matter.

The workshop addressed the basic aspects of active matter and some examples of its relevant applications nowadays. Overall, the focus of the workshop was to bring closer some of the main characteristics of active matter through interactive simulations that give a qualitative idea of active behaviour and the effect of different parameters on it.

Stay tuned for more activities like this!

Jesus Manuel Antunez Dominguez's presentation at Ämnets dag.
Jesus Manuel Antunez Dominguez’s presentation at Ämnets dag. Image by L. Natali.
Laura Natali's presentation at Ämnets dag.
Laura Natali’s presentation at Ämnets dag. Image by L. Natali.

Chun-Jen Chen attended the “Mobility, self-organization and swimming strategies” school, 18-29 October 2021

The school brought about a new collaboration on a simulation project with Vicsek-like model in complex environment (an example in upper with swimmers in black arrows showing their orientations), e.g. a turbulent flow (heatmap in upper panel), considered microswimmers that try to align to neighbors in a spatially-correlated noise (cartoon in lower). (Image by C-J Chen.)
From the 18th to the 29th of October 2021, Chun-Jen and two of his colleagues working on programmable active Janus colloids participated in the The 1st UCA FOX, UCA Fall program on Complex Systems 2021 “Mobility, self-organization and swimming strategies” hosted by Université Côte d’Azur in Nice and Fréjus.

The school was focused on three main topics: Swimming into complex environment – micro-swimming, Collective motion, and Machine learning applied to active particles, and covered a wide range of models regarding chemical and biological microswimmers.

The school was organised in lecture sections and project sessions for participants to collaborate in groups, in which PhD students and post-doctoral researchers could develop a research project in one of the three main topics of the school. Chun-Jen was involved in a simulation project on a Vicsek-like model in complex environment which is still ongoing.

Jesús Domínguez’s secondment at the University of Gothenburg

Jesus Manuel Antunez Dominguez during his secondment in the University of Gothenburg. Image by L. Natali.
Jesús Manuel Antúnez Domínguez visited the University of Gothenburg (Sweden) from the 27th of October to the 11th of November 2021 during a two weeks secondment.

The University of Gothenburg is the academic collaborator of his industrial PhD project at Elvesys (France). During the secondment, he could meet his academic supervisor Dr. Caroline Beck Adiels and the rest of her group, the Biological Physics Lab, but also, the Soft Matter Lab researchers who work closely with them. The secondment served to become familiar with the facilities available at the University and it was a great opportunity to participate in outreach activities and present the progress of his project to establish new collaborations for the research about Active Matter.

Audrey Nsamela presented a poster at MicroTAS 2021 hybrid conference in Palm Springs

The Miniaturized Systems for Chemistry and Life Sciences (or MicroTAS) conference took place this year on October 10-14th in a hybrid configuration, both online and in-person in Palm Springs (USA). This conference unite top researchs groups from all over the world and present the most recent advances in MEMS. Audrey attended the conference online from Paris and presented her poster on the development of a sperm sorting platform including chemotaxis guidance.

Audrey Nsamela and Jesús Domínguez both present a poster at MNF conference in Toulouse

The Micro-Nano-Fluidics meeting took place in Toulouse (France) in September 2021. This conference was organized by a french research group and covered mainly 6 topics: Nanofluidics, Chemical Engineering, Flow-waves interactions, Flow chemistry, Diagnostics and clinics, Organ-on-Chip. Audrey and Jesús attended the 2 days conference and presented their poster. Audrey’s poster was focused on the development of a microfluidic platform for sperm sorting, while Jesús’s poster described his work on microfluidic droplet generation for bacteria encapsulation and biofilm studies. This national conference was a great opportunity for both ESRs to meet other researchers in microfluidics and discuss about applications in Active Matter.

Group picture.