Roughness induced current reversal in fractional hydrodynamic memory.

Prior research has shown that corrugated surfaces are common in biological systems and influence transport phenomena. It was already known that subdiffusive media exhibit memory effects in particle movement. However, the role of surface roughness in current reversal remains unclear. No prior work had resolved whether rough surfaces could reverse transport direction in fractional hydrodynamic memory systems. This gap motivated investigations into how roughness affects particle transport under external forces. That uncertainty drove the need to explore energy conversion mechanisms in subdiffusive environments. The lack of understanding about how ratchet geometry influences current reversal also remains unresolved. These questions highlight the need for new models that incorporate roughness and memory effects together.

The study aims to determine if rough surfaces induce current reversal in subdiffusive media with fractional hydrodynamic memory. It seeks to analyze how roughness affects transport direction and magnitude. The specific problem involves understanding the interplay between surface features and external forces. The motivation comes from the need to explain transport reversal in biological and engineered systems. The study also aims to explore how energy is converted and dissipated in such systems. It seeks to clarify the role of ratchet geometry in controlling transport behavior. The purpose includes identifying how temperature and friction influence transport stability. These goals address gaps in understanding transport mechanisms in complex media.

The investigation uses a rough potential model to simulate particle transport in subdiffusive media. Fractional hydrodynamic memory is incorporated through a memory kernel in the Langevin equation. External forces are applied to drive particle movement against a load. The transport is analyzed using subdiffusion coefficients and Peclet numbers. Thermodynamic efficiency is calculated to assess energy conversion processes. The study tracks useful work and input power to quantify energy partitioning. Ratchet geometry is varied to test its effect on current reversal frequency. The analysis combines numerical simulations with theoretical modeling of memory effects.

The strongest finding is that roughness induces current reversal in subdiffusive systems with memory effects. Transport transitions from no movement to directed motion under rough surface conditions. The analysis shows that periodic forces convert into mechanical energy to drive transport. Energy dissipation occurs through environmental absorption in subdiffusive media. Peclet numbers indicate that roughness enhances transport efficiency. Thermodynamic efficiency reveals that temperature and friction control system stability. Ratchet size and shape determine when current reversal occurs and how often. The findings suggest that roughness plays a critical role in directing particle transport.

The authors propose that roughness can reverse transport direction in systems with fractional hydrodynamic memory. They suggest that transport results from partial energy conversion into mechanical work. The study indicates that roughness enables transitions from no transport to directed motion. The findings imply that ratchet geometry controls current reversal frequency and occurrence. Thermodynamic efficiency is shown to depend on temperature, friction, and load. The authors propose that these mechanisms may explain dynamics in biological systems. They suggest that roughness and memory effects together influence transport stability. The conclusions highlight the relevance of these findings to particle separation at the mesoscopic scale.