Engineering ratchet-based particle separation via extended shortcuts to isothermality

Area of Science:

• Statistical physics
• Thermodynamics
• Particle separation science

Background:

• Microscopic particle separation is crucial but conventional methods have limitations.
• Ratchet-based separation offers promise but lacks theoretical energy analysis.
• Energetically efficient separation is a key challenge in the field.

Purpose of the Study:

• To develop a nonequilibrium thermodynamic approach for controllable, low-energy particle separation.
• To theoretically analyze energy consumption in ratchet-based separation processes.
• To bridge the gap between thermodynamic control and particle separation optimization.

Main Methods:

• Utilized a nonequilibrium thermodynamic approach extending shortcuts to isothermality.
• Designed a temporal periodic ratchet potential for overdamped Brownian particles.
• Analyzed average particle velocity and derived the lower bound for energy cost.
• Numerically tested findings using a sawtooth potential and demonstrated 2D scalability.

Main Results:

• Achieved controllable separation of particles with different diffusion coefficients.
• Found particle velocity is proportional to (1-D/D*)τ⁻¹ in the slow-driving regime.
• Determined an energy cost lower bound dependent on driving dynamics and thermodynamic length.
• Demonstrated optimal separation protocols and compared performance with conventional ratchets.

Conclusions:

• The proposed method enables efficient and controllable particle separation with low energy cost.
• The theoretical framework provides insights into the energetic limitations and optimization of ratchet separation.
• This work paves the way for advanced thermodynamic optimization in particle separation technologies.