CECAM

Emerging behaviour in active matter: computational challenges

Location : University of Lincoln, Lincoln, UK
June 27, 2019 – June 29, 2019

Active Matter systems consist of self-propelling particles (SPP) which can collectively form out-of-equilibrium stationary states which exhibit structural and/or dynamical order unseen in the equilibrium realm [1]. Computer simulation of these systems is a fast developing field at the interface of physics, mathematics, chemistry, biology and engineering design. Examples of SPP systems found in nature are: flocks of birds, schools of fishes, bacteria colonies, etc. Recently, assemblies of robots, as models for SPP, have entered the field of study both experimentally and simulation wise [2]. One may distinguish SPP systems of two types. In the first type the systems consist of particles interacting via the background in which they are moving. The driving forces are due to the gradients of chemical or physical factors, such as fluid flows, concentrations, temperature, light, electric and magnetic fields, etc [3]. The systems of this type have two general classes: non-biological and biological ones. Non-biological ones include so-called active colloids [4], which are reaction-driven swimmers with their behaviour being influenced by colloids size, shape, and relative importance of surface activity, responsible for the chemical reaction, versus mobility (fluid media viscosity) [5, 6]. Another example is particles propelled by external fields, such as magnetic field [7, 8] or gravity [9]. Collective behaviour of these systems (such as phase separation) is rather different compared to passive particles [10]. The biological class ranges from active bio-molecules to organisms. Example of active behaviour in bio-molecular systems is motility of microtubules assisted by kinesin motor proteins [11, 12]. A very large part of biological systems of this class is represented by moving organisms in fluids (microswimmers [13]) or on substrates (cells crawling) [14]. 
The second type is formed by systems of particles, which interact via kinematic constraints imposed on their velocities. An example is a system where particles adjust the direction of their velocities to the direction of the average velocity in their neighbourhood [15]. Realization of such constraints requires exchange of information (visual or other sensorial means) between the particles and their environment. Considerable effort in this subfield is devoted in proposing microscopic models for the particle interaction (either potential or non-potential), which could mimic collective biological behaviour of flocks of birds, schools of fishes [1], large groups of robots [2], etc. The first numerical model for coherent motion of such SPP was proposed by Vicsek et al. [15], which since evolved into a large subfield [16-18]. Very recently, a hybrid systems (combining the two types above) were investigated as well, where SPP with kinematic constraints (school of fish) are considered together with the effect of the surrounding flow [19]. Apart of the particle based simulations, a large effort is being invested in deriving and proposing effective numerical methods for hydrodynamic-like equations for collective motion of SPP [20-24].

References

[1] Fodor, E; Marchetti, MC, Physica A, 504, 106 (2018).
[2] Deblais, A; Barois, T; Guerin, T; Delville, PH; Vaudaine, R; Lintuvuori, JS; Boudet, JF; Baret, JC; Kellay, H, Physical Review Letters,120, 188002 (2018).
[3] Yoshinaga, N & Liverpool, T, Physical Review E. 96, 020603(R) (2017).
[4] Santiago, I, Nano Today, 19, 11 (2018) 
[5] Ibrahim, Y; Golestanian, R; Liverpool, TB, Phys. Rev. Fluids, 3, 033101 (2018).
[6] Safdar, M; Khan, SU; Janis, J, Adv. Materials, 30, 1703660 (2018).
[7] Garcia-Torres, J; Calero, C; Sagues, F; Pagonabarraga, I; Tierno, P, Nature Comm., 9, 1663 (2018).
[8] Han, K; Shields, CW; Velev, OD, Adv. Functional Materials, 28, 1705953 (2018).
[9] Kuhr, JT; Blaschke, J; Ruhle, F; Stark, H, Soft Matter, 13, 7548 (2017).
[10] Bruss, IR; Glotzer, SC, Physical Review E. 97, 042609 (2018).
[11] Kim K; Yoshinaga, N; Bhattacharyya, S; Nakazawa, H; Umetsu, M; and Teizer, W, Soft Matter, 14, 3221 (2018).
[12] Maryshev, I Marenduzzo, D, Goryachev, AB, Morozov, A, Physical Review E. 97, 022412 (2018).
[13] Oyama, N.; Molina, J. J.; Yamamoto, R, J. Phys. Soc. Japan, 86, 101008 (2017).
[14] Schnyder, SK; Molina, JJ; Tanaka, Y; Yamamoto, R, Sci. Reports, 7, 5163, (2017).
[15] Vicsek, T; Czirók, A; Ben-Jacob, E; Cohen, I; Shochet, O, Physical Review Letters, 75, 1226 (1995).
[16] Gregoire, G; Chate, H, Physical Review Letters, 92, 025702 (2004).
[17] Peruani, F; Aranson, IS, Physical Review Letters, 120, 238101 (2018).
[18] Mahault, B; Jiang, XC; Bertin, E; Ma, YQ; Patelli, A; Shi, XQ; Chate, H, Physical Review Letters, 120, 258002 (2018).
[19] Filella, A; Nadal, F; Sire, C; Kanso, E; Eloy, C, Physical Review Letters, 120, 198101 (2018).
[20] Toner, J; Tu, Y, Physical Review E. 58, 4828 (1998).
[21] Ramaswamy, S; Simha, R, Physical Review Letters, 89, 058101 (2002).
[22] Ratushnaya, VI; Bedeaux, D; Kulinskii, VL; Zvelindovsky, AV, Physica A, 381, 39 (2007).
[23] Chepizhko, O; Kulinskii, V, Physica A, 415, 493 (2014).
[24] Filbet, F; Shu, CW, Mathematical Models & Methods in Appl. Sciences, 28, 1171 (2018).

Austria

Oleksandr Chepizhko (University of Innsbruck)

France

Eric Clément (invited speaker) (PMMH-ESPCI & Sorbonne University, Paris)
Luis Gómez (Université Nice Sophia Antipolis)
Werner Krauth (invited speaker) (Ecole Normale Superieure Paris)
Philippe Marcq (invited speaker) (Sorbonne Université & ESPCI, Paris)
Fernando Peruani (invited speaker) (Université Nice Sophia Antipolis)

Germany

Markus Baer (invited speaker) (PTB, Berlin, Germany)
Paolo Malgaretti (invited speaker) (Max Planck Institute for Intelligent Systems)
Holger Stark (invited speaker) (TU Berlin)

Italy

Roberto Di Leonardo (invited speaker) (Sapienza Università di Roma)

Japan

Kenta, Chaki (JSOL Corporation)
Kenta Ishimoto (invited speaker) (University of Tokyo)
Natsuhiko Yoshinaga (invited speaker) (WPI Advanced Institute for Materials Research (WPI-AIMR), Tohoku University)

Singapore

Qunli Lei (Nanyang Technological University)
Ran Ni (invited speaker) (Nanyang Technological University)

Switzerland

François Lavergne (invited speaker) (Université de Fribourg)
Ignacio Pagonabarraga (invited speaker) (CECAM EPFL)

Ukraine

Vladimir Kulinskii (invited speaker) (Odessa University, Ukraine)

United Kingdom

Ronojoy Adhikari (invited speaker) (University of Cambridge)
Sami Al-Izzi (University of Warwick/Institut Curie)
Javier Diaz (University of Lincoln)
Arthur King (Warwick University)
Ryan Keogh (Loughborough University)
Christopher Lakey (University of Warwick)
Alexander Morozov (invited speaker) (University of Edinburgh)
Majid Mosayebi (invited speaker) (University of Bristol)
Matthew Turner (invited speaker) (University of Warwick)
Kristian Thijssen (Oxford University)
Julia Yeomans (invited speaker) (Oxford University)

USA

Igor Aronson (invited speaker) (Penn State University)

The booklet is available here 

Day 1 – Thursday, 27 June, morning

09:00 – 09:10 Welcome: Andrei Zvelindovsky (Lincoln)

Chair: Eric Clément (Paris)

09:10 – 09:35 Werner Krauth (Ecole Normale Supérieure, Paris, France)

Thermodynamic phases in active two-dimensional matter

09:35 – 10:00 Paolo Malgaretti (Max Planck Institute for Intelligent Systems, Stuttgart, Germany)

Dynamics of active polymers

10:00 – 10:25 Coffee Break

10:25 – 10:40 Arthur King (University of Warwick, UK)

Neighbour correlation and long-range interactions in flocking models

10:40 – 11:05 Ignacio Pagonabarraga (CECAM, EPFL, Switzerland)

Activity induced phase transitions: from MIPS to chiral self-sorting

11:05 – 12:00 Q&A and discussion

12:00 – 13:30 Lunch

Day 1 – Thursday, 27 June, afternoon

Chair: Ignacio Pagonabarraga (Lausanne)

13:30 – 13:55 Igor Aronson (Pennsylvania State University, USA)

Phase-field approach to cell motility in 2-D and 3-D

13:55 – 14:20 Ran Ni (Nanyang Technological University, Singapore)

Non-equilibrium etrongly hyperuniform fluids with large local density fluctuations – towards perfect photonic fluids

14:20 – 14:45 Stark Holger (Technical University of Berlin, Germany)

Emerging collective dynamics of spherical microswimmers: Role of hydrodynamic and chemotactic fields

14:45 – 15:15 Coffee Break

15:15 – 15:40 Roberto Di Leonardo (Sapienza University of Rome, Italy)

Light-matter-life interactions at the micron scale

15:40 – 16:05 Julia M Yeomans (University of Oxford, UK)

Modelling collective cell mechanics

16:05 – 17:05 Q&A and discussion

18:00 – 22:00 Social Dinner

Day 2 – Friday, 28 June, morning

Chair: Ryoichi Yamamoto (Kyoto)

09:00 – 09:25 Eric Clément (ESPCI-Sorbonne University, Paris, France)

Spontaneous and driven active matter flows

09:25 – 09:50 Alexander Morozov (University of Edinburgh, UK)

‘Superfluids’ vs collective motion in model active suspensions

09:50 – 10:15 Markus Bär (PTB, Berlin, Germany)

Emergence and control of patterns in active polar fluids

10:15 – 10:45 Coffee Break

10:45 – 11:00 Christopher Lakey (University of Warwick, UK)

Swimmers in smectics

11:00 – 11:25 Majid Mosayebi (University of Bristol, UK)

Amoeba-like living crystallites in electrically-driven colloidal rollers

11:25 – 12:25 Q&A and discussion

12:25 – 14:00 Lunch

Day 2 – Friday, 28 June, afternoon

Chair: Fabien Paillusson (Lincoln)

14:00 – 14:25 François A. Lavergne (University of Fribourg, Switzerland)

Group formation and cohesion of active particles with visual perception-dependent motility

14:25 – 14:50 Fernando Peruani (University Côte d’Azur, Nice, France)

Intermittent motion across scales in biology

14:50 – 15:15 Kenta Ishimoto (University of Tokyo, Japan)

A data-driven multi-scale modelling for collective dynamics of human sperm

15:15 – 15:45 Coffee Break

15:45 – 16:10 Philippe Marcq (Sorbonne Université, Paris, France)

An example of mechanical cell competition

16:10 – 16:35 Matthew Turner (University of Warwick, UK)

Intrinsically motivated collective motion

16:35 – 16:50 Oleksandr Chepizhko (University of Innsbruck, Austria)

Circle swimmers in crowded environments

16:50 – 17:50 Q&A and discussion

17:50 – 19:30 Poster Session and Reception (sponsored by JSOL)

Day 3 – Saturday, 29 June, morning

Chair: Alexander Morozov (Edinburgh)

09:00 – 09:25 Vladimir Kulinskii (Odessa National University, Ukraine)

Hydrodynamics for the Vicsek-type model of self-propelled particles: The Euler-Vicsek equation

09:25 – 09:50 Natsuhiko Yoshinaga (Tohoku University, Sendai, Japan)

Collective behaviours of dense active suspensions: the role of hydrodynamic lubrication

09:50 – 10:05 Sami Al-Izzi (University of Warwick, UK)

Activity driven shear instabilities in membrane tubes

10:05 10:35 Coffee Break

10:35 – 11:00 Xiaohu Guo (Hartree Centre, STFC, UK)

Developing an extensible, portable, scalable toolkit for large scale parallel particle method based applications

11:00 – 11:25 Ronojoy Adhikari (University of Cambridge, UK)

Chemical and hydrodynamic interactions between autophoretic colloids

11:25 – 12:30 Q&A, discussion and closing remarks

12:30 – 14:00 Lunch