Figure 8.

(a) Complex trajectory of the mechanical worm (MW) model through a lattice where R/L = 0.121, q/L = 0.331 and 𝒲 = 14.1 (see orange squares in figure 7). In the main image, the position of the centreline is plotted every undulation period and the asterisk indicates the MW's initial position. The accompanying panels show the details of the centreline motion for the indicated portions of the trajectory where the MW moves (A) along the 2–1 diagonal, (B) turning and weaving through the lattice, and (C) swimming between the rows of pillars. The inset panels show the details of the undulations in these three modes. (b) The scaled speed, V/(fL), as a function of time scaled by the period of undulations. The shaded areas correspond to the time windows shown in each of the insets A, B and C, respectively.