Programmable Elastic Metamaterials

Abstract

We introduce a novel concept for the design of programmable-elasticity metamaterials; materials whose elastic properties can be modified instantaneously and reversibly on demand. Real-time tunable linear and nonlinear elastic moduli are obtained in lattice materials by adjustment of strut connectivity via actuation of embedded electromagnetic locks. The Young's modulus and Poisson's ratio of prototype 2D materials are varied instantaneously by more than 2 orders of magnitude and between 0.15 and 0.9, respectively. The buckling strength of the structure is altered by an order of magnitude between two bifurcation states associated with a centrosymmetric and an anti-chiral buckling pattern.

Multistable Shape‐Reconfigurable Architected Materials

“…For example, a multistable reconfigurable material can be compressed significantly to be transported with considerably less cost before deployment; or it can be used to fabricate tools with multiple stable shapes for different purposes. Other foreseeable applications include energy and impact absorption, tunable phononic response, vibration isolation, and programmable metamaterials . Several strategies toward this goal have already been proposed, including foldable origami, tension controlled tensegrity structures, shape memory morphing materials and structures, shape‐shifting jamming materials, and modular self‐assembled structures .…”

An Active Microarchitectured Material that Utilizes Piezo Actuators to Achieve Programmable Properties

“…Hydraulic pressure has also been used to stiffen composites filled with fluid and pneumatic pressure has been used to stiffen structures via particle jamming . A microarchitectured material design was recently proposed that utilizes electromagnetic locks to achieve discrete stiffness values, which approach continuity as the number of on‐off locks within the lattice increases . A key difference between these materials and the material proposed here is that the proposed material can be programmed to exhibit desired combinations of multiple properties simultaneously (e.g., Young's Modulus, Poisson's ratio, density, and damping coefficient) that can be maintained at constant values over appreciable deformations or actively tuned in a purely continuous way according to instructions uploaded within independently controlled unit cells.…”

Harnessing Magnets to Design Tunable Architected Bistable Material

“…Practically, traditional shape‐reconfigurable materials can only operate in a fixed mode: monostable, bistable, or multistable. Currently, the mode transformation of the SRMs can be attained through three ways: 1) adjusting the strut connectivity of lattice material or switching deformation modes; 2) designing the unit architecture with programmable Poisson's ratio; 3) combining with hierarchical design methods by depositing metallic nanofilms on pre‐stretched elastomer substrate . However, the above methods are actually “one‐time writing‐in” methods, which means once the materials are fabricated, the performances are set, and can not be adjusted anymore, which limits the applications of the material in engineering.…”