Autonomous Motion toward the Dark Region

By taking the slope of the curve for the evolution of the %-coordinate at relatively early times (but after the oscillations are fully developed within the sample), we find that gel s velocity for the reference value of x = 0.105 along the x-direction is approximately 0.03 in the dimensionless units. The latter value of velocity 

3 Light-Cuided Motion along Complex Paths 

As we show herein, the BZ gels can autonomously bend and make various turns as they effectively sense the variations in the illumination. Hence, these gels are not constrained to move along a sole direction, but can follow a complicated path as they navigate away from the light and, thus, could ultimately perform complex maneuvers and tasks (e.g., carry a payload to specified locations). 

To mimic variations in the light intensity, in the simulations, we alter the value of I) (see Equation 3.22 and discussion in Section 3.3.1). Specifically, within the noniUuminated, dark regions, we set I) = 0. Within the illuminated regions, we set I) = 1.95 X 10. As the worm starts to move out of this illuminated area, we update the value of I , setting it to zero for those gel elements that are now localized in the dark region. 

1) Even in the absence of light, traveling waves will appear in this sample and can cause a macroscopic displacement of the gel however, there is no preferred direction for the wave propagation, so the probabilities of the 

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