Deep reactive ion etching of auxetic structures: present capabilities and challenges

• Published in: Smart materials and structures Vol. 23; no. 8; pp. 1 - 7
• Main Authors: Muslija, Alban, Díaz Lantada, Andrés
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.08.2014; Institute of Physics
• Subjects: Actuators; Auxetic materials; auxetics; Compressed; Densification; Devices; Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Metamaterials; morphing structures; negative Poisson ratio; Physics; Reactive ion etching; Stands; Transducers; Actuators; Reactive ion etching; Variable geometry; Manufacturing processes; Densification; Poisson ratio; Micromachining; Auxetic material; Mechanical properties; Metamaterial
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/23/8/087001

Auxetic materials (or metamaterials) have negative Poisson ratios (NPR) and display the unexpected properties of lateral expansion when stretched, and equal and opposing densification when compressed. Such auxetic materials are being used more frequently in the development of novel products, especially in the fields of intelligent expandable actuators, shape-morphing structures and minimally invasive implantable devices. Although several micromanufacturing technologies have already been applied to the development of auxetic materials and devices, additional precision is needed to take full advantage of their special mechanical properties. In this study, we present a very promising approach for the development of auxetic materials and devices based on the use of deep reactive ion etching (DRIE). The process stands out for its precision and its potential applications to mass production. To our knowledge, it represents the first time this technology has been applied to the manufacture of auxetic materials with nanometric details. We take into account the present capabilities and challenges linked to the use of DRIE in the development of auxetic materials and auxetic-based devices.