Activity-assisted barrier-crossing of self-propelled colloids over parallel microgrooves

TL;DR

This study investigates how self-propelled colloids navigate over microstructured landscapes, revealing that their escape behavior can be modeled by an effective potential incorporating self-propulsion, with implications for understanding active matter transport.

Contribution

It introduces a quantitative framework for describing the escape dynamics of self-propelled particles over patterned microgrooves, integrating self-propulsion into an effective potential model.

Findings

Escape dynamics are well-described by an effective potential including self-propulsion.

Parallel microgrooves enable controlled study of activity and confinement effects.

Thermal noise influences the transport and escape behavior of active particles.

Abstract

We report a systematic study of the dynamics of self-propelled particles (SPPs) over a one-dimensional periodic potential landscape, which is fabricated on a microgroove-patterned polydimethylsiloxane (PDMS) substrate. From the measured non-equilibrium probability density function of the SPPs, we find that the escape dynamics of the slow-rotating SPPs across the potential landscape can be described by an effective potential, once the self-propulsion force is included into the potential under the fixed angle approximation. This work demonstrates that the parallel microgrooves provide a versatile platform for a quantitative understanding of the interplay among the self-propulsion force, spatial confinement by the potential landscape, and thermal noise, as well as its effects on activity-assisted escape dynamics and transport of the SPPs.