Brownian diode: Molecular motor based on a semi-permeable Brownian particle with internal potential drop

► We suggest a new model of autonomous isothermal Brownian motor. ► The motor is a Brownian object which is semi-permeable for molecules of surrounding thermal bath. ► The internal propulsion force is generated by a potential drop which the molecules experience inside the particle. ► An analytical result for the stationary drift velocity is obtained and supported by numerical simulation.