Self-Assembly of Dimer Motors under Confined Conditions

Chemically synthetic nanomotors can consume fuel in the environment and utilize the self-generated concentration gradient to self-propel themselves in the system.We study the collective dynamics of an ensemble of sphere dimers built from linked catalytic and noncatalytic monomers.Because of the confinement from the fuel Held and the interactions among motors,the ensemble of dimer motors can self-organize into varlous nanostructures,such as a radial pattern in the spherical fuel field and a staggered radial pattern in a cylindrical fuel Held.The influence of the dimer volume fraction on the self-assembly is also investigated and the formed nanostructures are analyzed in detail.The results presented here may give insight into the application of the self-assembly of active materials.

Rotational effect in two-dimensional cooperative directed transport

In this review we investigate the rotation effect in the motion of coupled dimer in a two-dimensional asymmetric periodic potential. Free rotation does not generate directed transport in translational direction, while we find it plays an critical role in the motors motility when the dimer moves under the effect of asymmetry ratchet potential. In the presence of external force, we study the relation between the average current and the force numerically and theoretically. The numerical results show that only appropriate driving force could produce nonzero current and there are current transitions when the force is large enough. An analysis of stability analysis of limit cycles is applied to explain the occurrence of these transitions. Moreover, we numerically simulate the transport of this coupled dimer driven by the random fluctuations in the rotational direction. The existence of noise smooths the current transitions induced by the driving force and the resonance-like peaks which depend on the rod length emerge in small noise strength. Thanks to the noise in the rotational direction, autonomous motion emerges without the external force and large noise could make the current reversal happen. Eventually, the new mechanism to generate directed transport by the rotation is studied.

Transport of nanodimers through chemical microchip

We propose a new microfluid chip for transporting micro and nano particles.The device consists of chemical stripe pathways full of fuel species,which can be realized in experiments by chemical surface reactions that form spatiotemporal patterns.A mesoscopic model is constructed to simulate the transport dynamics of nanodimers passing through the chip.It is found that the increases of the volume fraction and radius of the dimer both decrease the first reach time although the underlying mechanisms are different:the volume fraction affects the probability of touching and entering the chip while the radius determines the self-propulsion within the chip.The transport efficiency is influenced by the size of the particles.

Dynamics of Spiral Waves Induced by Periodic Mechanical Deformation with Phase Difference

The dynamics of spiral waves under the influences of periodic mechanical deformation are studied. Here,the mechanical deformation propagating along the medium with phase differences are considered. It is found that weak mechanical deformation may lead to resonant drift of spiral waves. The drift direction and velocity can be changed by the wave length of the deformation. Strong mechanical deformation may result in breakup of spiral waves. The characteristics of breakup are discussed. The critical amplitudes are determined by two factors, i.e. the wave length and frequency of the periodic mechanical deformation. When the wave length of mechanical deformation is comparable to the spiral wave, simulation shows that the critical amplitude is substantially increased. As the frequency of the mechanical deformation is around 1.5 times of the spiral wave, the critical amplitudes are minimal.

A dynamical transition of a chain of charged particles in a 2D substrate potential

The transport of a chain of charged particles with a transverse degree of freedom is investigated in a 2D asymmetric potential.Here,the energy of the periodic driving force is converted into motion in the vertical direction.The analysis exhibits a transition from stick-slip motion to periodic oscillation.The chain velocity can be controlled to an optimized value by adjusting system parameters,such as the amplitude and frequency of the periodic force.The existence of a resonance platform indicates resonance between the motion of the chain and the periodic force as coupling strength increases adiabatically.The atomic configuration and the transverse degree of freedom also play key roles in the control.