Confinement-Driven Acceleration of First-Passage Rates

TL;DR

This paper shows how confinement geometry can enhance diffusion efficiency by accelerating first-passage times, with implications for biological and soft matter transport processes.

Contribution

It introduces an analytic framework combining Fick-Jacobs theory and simulations to demonstrate confinement's role in optimizing first-passage rates beyond free diffusion.

Findings

Confinement can nonmonotonically affect first-passage times.

Optimal confinement geometries enhance transport efficiency.

Results have implications for molecular translocation and reaction kinetics.

Abstract

We demonstrate that confinement geometry can act as a rectifier in passive diffusion, optimally accelerating first-passage rates beyond free diffusion. Using analytic theory based on the Fick-Jacobs approach and Brownian dynamics simulations, we find nonmonotonic mean first-passage rates driven by entropy. Through the transmission probability, our findings highlight how confinement optimizes transport dynamics in trap-and-escape processes, with implications for molecular translocation and reaction kinetics in soft matter and biological systems.