MIT Develops Framework for 3D Woven Metamaterials with Programmable Properties

Researchers at the Massachusetts Institute of Technology (MIT) have developed a computational design framework that facilitates the creation of three-dimensional (3D) woven metamaterials with customizable mechanical properties. These metamaterials are composed of intertwined fibers that self-contact and entangle, resulting in unique behaviors.

Carlos Portela, the Robert N. Noyce Career Development Professor and associate professor of mechanical engineering at MIT, highlighted the significance of this development for emerging engineering challenges in areas such as soft robotics, biomedical devices, wearable devices, and functional textiles.

The framework, detailed in a paper published on January 26 in Nature Communications, provides open-source code that allows users to design metamaterials tailored to specific specifications and generate files suitable for 3D printing or simulation. This approach enables the creation of complex 3D woven structures with a wide range of properties.

Portela noted that traditional knitting or weaving has been limited by hardware constraints for centuries, resulting in a limited number of patterns for clothing. He emphasized that this new framework overcomes such limitations, allowing for the development of innovative patterns that can significantly alter the behavior of textiles.

The research team developed general design rules in the form of an algorithm that provides a graph representation of the metamaterial. This graph dictates the placement and connection of each fiber within the material. The fundamental building blocks are woven unit cells that can be functionally graded by controlling various design parameters, such as the radius and pitch of the fibers that make up the woven struts.

Lead author Molly Carton, a former postdoctoral researcher in Portela's lab and now an assistant research professor in mechanical engineering at the University of Maryland, explained that the framework allows these metamaterials to be tailored to be softer in one place and stiffer in another, or to change shape as they stretch. This capability enables an exceptional range of behaviors that would be challenging to design using conventional soft materials.

The simulation framework also enables users to predict the deformation response of these materials, capturing complex phenomena such as self-contact within fibers and entanglement. This predictive capability allows for the design of materials that can resist deformation or tearing patterns.

Portela expressed excitement about the ability to tailor failure in these materials and design arbitrary combinations. Based on simulations, the team was able to fabricate spatially varying geometries and conduct microscale experiments.

This work is the first to provide a tool for users to design, print, and simulate an emerging class of metamaterials that are extensible and tough. It demonstrates that by tuning geometric parameters, users can control and predict how these materials will deform and fail. The research presents several new design building blocks that substantially expand the property space of woven metamaterials.

Carton believes the framework will be useful across many disciplines. By releasing this framework as a software tool, the team hopes that other researchers will explore the possibilities using woven lattices and find new ways to utilize this design flexibility. She looks forward to seeing the opportunities that this work can open.