WEB On the way to mass production of programmable and auxetic materialsTuesday (22.09.2020) 16:10 - 16:25 F: Functional Materials, Surfaces, and Devices 2 Part of:
Programmable and auxetic materials attain big interest in the academic sector, but suffer a lack of application in the industry. Auxetic materials exhibit unique properties which are not found in nature, whereas programmable materials have the potential to replace traditional sensor – signal processing – actor chains by using a defined inner structure of the material. The inner structure can be formed by small repeating building blocks, the unit-cells.
The main challenges of introducing the new material concept into industrial applications are within the production techniques and the shift of the mind set of potential users towards the paradigm change arising from the use of programmable materials. The latter challenge is faced by the development of a web-based tool within the Fraunhofer Cluster Programmable Materials CPM, reflecting the complete design and production chain and serving as an easy to use support for potential users of programmable materials. The production aspect will be discussed in this paper.
In the academic sector, additive manufacturing methods, useful for the production of small lots are often used for manufacturing demonstration parts of programmable materials which often serve as study objects to learn about the design and optimization of the unit cells and their combinations. An intensive screening of various processing techniques in view of their potential to produce small 3D-structures forming the unit-cells in high quantities and three dimensions was performed, which led to the choice of two promising techniques which are currently under consideration: Textile techniques and the stacking of 3D-structured planes produced by thermoforming.
Textile techniques exhibit a huge versatility regarding the available materials: natural, synthetic, ceramic and metallic fibres or filaments can be used in various techniques like weaving, braiding or knitting, leading to structures with a huge mechanical and deformation property spectrum. One example for a conversion of a previously developed unit cell for production with textile techniques will be displayed.
The process of stacking of polymeric thermoformed structured planes is presented and discussed in view of the material choice, possible shaping techniques for the single planes as well as suitable connection and joining techniques. An example material based on auxetic Miura-Ori structures is presented and the mechanical and deformation properties of the structure are discussed.