About the Paper

The Project

Porous structural materials with well-defined periodicity are ubiquitous not only in nature but also in synthetic structures and devices. These types of materials have been proven to offer various types of auxetic behavior, ranging from negative Poisson’s ratio to high energy absorption and excellent acoustic damping. Yet, here we present a novel auxetic behavior harnessed by introducing angled cuts into a periodic porous material. Using this approach, we utilize out-of-plane behavior with the potential to control friction, light emission and reflection, as well as fluid flow properties. Using a combination of physical experiments and non-linear finite element analysis, we study the effects of geometry on creating and propagating this out-of-plane auxetic behavior.

 

Abstract

Porous materials with well-defined periodicity are commonly encountered in biological and synthetic structures and exhibit a wide range of behaviors, ranging from negative Poisson's ratios, to high energy absorption and acoustic damping. Recently, the response of these systems has been shown to be enhanced by mechanical instabilities that lead to sudden and reversible geometric transformations. Although buckling induces planar transformations in most of 2D porous metematerials, here we describe the emerging of 3D morphologies triggered by mechanical instabilities in an elastomeric block with tilted cylindrical holes. As a proof of concept, we also demonstrate that these structures can be leveraged to tune surface properties including friction and light reflection, thus providing a new experimental platform for investigating deformation-dependant dynamics for tribological and optical applications.

 

Supporting Material

All supporting videos can be found here: VIDEOS

All supporting information can be found here: SUPPLEMENTARY INFORMATION

Code and Data

To download the entire repository you may use this link: Download Here

The repository is devided into two sections:

1. Analysis Files

2. Python Generation Files

3. Fluid Cavity Models

If there are additional suggested changes or improvements to the code, please submit a GitHub pull request and contact me at contact.