PMC

A schematic of the trajectory of a cell migrating within an electric field. The black line indicates the electric field vector from cathode to anode and the blue line shows the trajectory of the cell in time. The red line represents the overall displacement of the cell. The angle between the electric field vector and the cell displacement vector is labeled θ.

Microflow generation by homogeneous oscillating electric fields in simple nematic cells. (a) A schematic of a planar cell with a vertically applied electric field. Director tilt angle and the velocity profile are shown as the electric field is turned on (b) and off (c). In both cases, the fluid motion is bidirectional. The maximum displacement of the nematic molecules is  ≈ 0.06 h. The dotted line for the director tilt angle in (b) shows the director profile when the electric field is switched off. There is a mismatch between the profiles, which leads to a slight difference in the maximum displacement of the bidirectional motion. The displacement for turning the electric field off is larger for  ≈ 0.002 h. (d) A schematic of the director field and the applied electric field for a HAN cell. (e,f) Director and velocity profiles for turning the electric field on and off, respectively. During the switching process, there is a momentary average net flow in either left or right direction. (g) Applied voltage between top and bottom plate, average flow and average displacement for turning the electric field on. The averaging is performed across the whole cell height. After a long enough time an average displacement of  ≈ 0.009 h towards the left is established. (h) Measurement is repeated for turning the electric field off. A displacement of  ≈ 0.012 h towards the right is observed. (i) By applying a square-like voltage, we established a net average flow through a HAN cell. From the increasing average displacement in time, an average flow of 〈v〉_z,t = 2.4 ⋅ 10⁻³ h/τ_dir is calculated.

(a) Polaron displacement as a function of time for three different AGNRs families under the influence of different electric fields strengths. The red line represents a 4-AGNR under a field of 7220 V/cm. The green line represents a 5-AGNR for 2400 V/cm. The blue line represents a 6-AGNR 1200 V/cm. (b) Displacement as a function of time for two different families of bipolarons under the influence of different electric fields strengths. The red line represents a 4-AGNR under a field strength of 7220 V/cm. The blue line represents a 6x70-AGNR for 1200 V/cm.

Identification of the domain wall and 3D rendering of nanorod as a defect within the nanoparticle. a Variance of displacement in the nanoparticle under the maximum electric field E ₂ (223 kV cm⁻¹), calculated in the vicinity of the domain wall. b Variance of displacement in the nanoparticle under the electric field E ₃ (0 kV cm⁻¹) calculated in the vicinity of the domain wall. c Map of displacement values and magnification of the boxed region for the nanoparticle at the slice shown as green plane in f for the state at field E ₂ (223 kV cm⁻¹). d Displacement values as a function of position of lineplots in c. e Angular dependence of the displacement field and of the gradient of the displacement measured along the defect line in f with error bars indicating standard deviation over the slices in the particle. f Rendering of the particle under field E ₂ shows the 3D nanorod as a defect line whose 2D cross-section corresponds to the vortex core. Scale bars correspond to 60 nm