Interplay between elasticity and activity: from vibrated elastic particles to penetration of active particles through elastic membranes*

The interplay between elasticity and activity and lead to new nonequilibrium phenomena and novel material properties.

Here we first discuss the motion of self-propelled vibrated granulates with elastic legs leading to activity [1].
While inertia is usually neglected in standard models, the significance of inertia on macroscopic self-propelled particles is experimentally demonstrated. We observe a distinct inertial delay between orientation and
velocity of particles, originating from the finite relaxation times in the system. This effect is fully explained by an
underdamped generalisation of the Langevin model of active Brownian motion. In stark contrast to passive systems, the inertial delay profoundly influences the long-time dynamics and enables new fundamental strategies for controlling self-propulsion in active matter.

Second, analytical and simulational results for an active particle navigating against an elastic membrane
are proposed [2]. Basically there are three states:
i) penetration of the active particle through the membrane and healing of the membrane,
ii) penetration of the active particle through the membrane and descruction of the membrane,
iii) trapping of the active particle by the membrane.


[1] C. Scholz, S. Jahanshahi, A. Ldov, H. Lowen,
Inertial delay of self-propelled particles,
https://arxiv.org/pdf/1807.04357.pdf

[2] A. Daddi-Moussa-Ider, S. Goh, B. Liebchen, C. Hoell,
A. J. T. M. Mathijssen, F. Guzman-Lastra,
C. Scholz, A. M. Menzel, H. Lowen,
Membrane penetration and trapping of an active particle, preprint