4D Materiality (2018)

4D Materiality (2018)

Monique Bateman

Often we design strategically to cater the form of an object to the choice of material, however, we may not need to any longer. Due to recent advancements in multi-material 3D printing we could rather dream up an object and design a material with properties that work to its needs. Monique completed a research scholarship with supervisor Tim Miller and Material Scientist and Aeronautics Engineer Emilio Calius following her undergraduate degree. Together they combined their expertise and explored using multi-material 3D printing and algorithmic modelling software Grasshopper to develop a kind of Metamaterial called ‘Pentamodes’ which are a solid that behaves like a fluid. The project was completed in June 2018 and won 1st place in the Victoria University of Wellington Summer Gold Video Competition. Monique was also given the opportunity to present her research at the Manufacturing and Design Conference in May 2018.

Pentamode Structure Research

The complexity enabled by additive manufacturing processes combined with the relatively recent development of so-called digital materials offers unprecedented control over the effective material properties of objects, including spatial and time variations. New horizons in design are emerging where shape and materiality are both malleable and can be independently manipulated, transforming both functionality and aesthetics. As a demonstration of the emerging interchangeability of material and shape, we have experimented with its application to a mechanical metamaterial. Metamaterials are a class of structured, artificial materials whose properties are driven by their topological design, i.e. their shape. Pentamodes are a particularly interesting type of metamaterial for several reasons. Despite being a solid, they behave like a fluid under small deformations and their effective bulk modulus and mass density can be adjusted independently over a wide range. More importantly, theory predicts that they could be designed to possess any thermodynamically admissible elasticity tensor. In other words, pentamode metamaterials offer a promising path towards design control over effective mechanical properties

Novel Generative Design

Pentamode metamaterials are open lattice structures that derive their unique properties from the shape or geometry of the lattice struts and specially the connections between struts. Ideally these connections are point-like but in practice have a finite volume which introduces obvious practical difficulties. A new type of pentamode structure is proposed in which the lattice struts and their connections are kept uniform and instead the material of which they are composed is varied to achieve pentamode behavior. A generative model implemented in Grasshopper is combined with multi-material printing using a Stratasys PolyJet machine to create a series of 2D and 3D pentamode-like structures. Finite element simulations elucidate the similarities and differences between classical and these material-based pentamodes. 2D test articles are shown to experimentally display key pentamode characteristics.

Design Applications

Lastly Monique looked at design applications that take advantage of the Pentamode’s conceptualised technology. Firstly she developed a soft flexible helmet as the Pentamode allows shear flexibility while retaining structural integrity. This is where the fluid-like nature of the classic isotropic Pentamode is particularly interesting as we could vary the effective properties in a way that accommodate the human body comfortably. The helmet also covers the ears, which using the Pentamode’s ability to divert waves, could protect the user from damaging frequencies often heard in places such as construction sites, industrial machinery and extreme sport environments. The other application explored uses a Pentamode based material to passively manipulate waves over a wide frequency range, eliminating the need for active noise cancelling technology whose effectiveness is compromised by its limited frequency range and need for power. The Pentamode architecture can also provide the flexibility needed to achieve adaptability and comfort, because no ear is the same and our ears keep growing throughout our life.

From Summer Scholarship to Employee

After presenting her research at the MAD Conference Monique was approached by NZ Product Accelerator for a position as a Technologist in their core team in Auckland. She now uses her design skills to bridge the gap between academia and industry, working on diverse research and development projects with cross disciplinary teams that deliver real impact for New Zealand.

Materials and Processes – close up

Software

Rhino with the Grasshopper plug-in.

Hardware

Stratasys J750 printer

Project level

This project was undertaken as a Summer Research Scholarship and supervised by Tim Miller and Aeronautics Engineer Emilio Calius 

Summer Gold Competition 2018 Winner