Pruning bright bonds to engineer smart networks*

Disordered networks made of harmonic springs can be tuned to show various unconventional responses. For example, a network could be designed to respond to an input strain with a very specific localized output at a distant site. One could also modify a network’s global mechanical properties, such as the Poisson’s ratio. We have experimentally realized both of these in physical systems [1, 2]. There are multiple pruning algorithms that can achieve such responses. We are working on algorithms that could be applied on networks in situ. We make our networks out of photoelastic material and observe them between cross polarizers. This allows us to visualize the stress distribution in these networks under various deformations. With this technique, we can apply various algorithms to an experimental system. This enables us to design networks with desirable responses without any numerical calculations.
References:
[1] JW Rocks, N Pashine, I Bischofberger, CP Goodrich, AJ Liu, and SR Nagel, PNAS 114, 2520–2525 (2017)
[2] DR Reid, N Pashine, JM Wozniak, HM Jaeger, AJ Liu, SR Nagel, JJ de Pablo, arXiv: 1710.02493 (2017)