Fig. 4.

(A) Physical realization of the network in Fig. 1A. (Insets) Zoom-ins show the initial and final distance between the source nodes, $l_S$ and $l_S+e_S$, respectively, and between the target nodes, $l_T$ and $l_T+e_T$. The undeformed network is shown in black, and the deformed network is superimposed in red. (B) Photograph of a 3D network constructed by 3D printing with 33 nodes and 106 bonds at $\mathrm{\Delta }Z=\mathrm{\hspace{0.17em}0.42}$ tuned to exhibit a negative response ($\eta =-5.0$). (Insets) In the zoom-ins, the yellow and blue arrows show the distance between the undeformed, $l_S$ ($l_T$), and deformed, $l_S+e_S$ ($l_T+e_T$), source (target) nodes, respectively.