Fig. 5.

(A–D) Planar phototropic shape evolution for a fixed light source and with no axial growth, for small and large values of the ratio of response rate to transport rate $t_{\text{tran}}/t_{\text{photo}}$ and dimensionless bending length ${\ell }_{\text{bend}}=U/\left(QL\right)$. (A–D, Insets) Alignment is characterized by ${\mathsf{e}}_2\left(t\right)$, such that ${\mathsf{e}}_2=0$ when the tip is pointed at the source for this planar case. Further simulation details and parameters are provided in SI Appendix, section 8.