Showing papers in "Extreme Mechanics Letters in 2021"

TL;DR: A perspective on what PI paradigm is, when PI can be more significant and dominant in physical and biological agents at different length scales and how bioinspired and abstract PI methods can be created in agent bodies are given.

TL;DR: The present paper aims to give a review of the current use of additive manufacturing methods for the manufacturing of soft robots, finding three approaches to exploit AM in soft robotics: rapid mold fabrication, hybrid, and total additive manufacturing.

TL;DR: In this article, a review of recent progress in the development of triboelectric mechanical sensors for monitoring mechanical motion, mechanical vibration, mechanical pressure and mechanical tactile perception is presented.

TL;DR: A systematic topological optimization method based on material-field series expansion (MFSE) framework for full and directional band gap acoustic metamaterials design that can generate meaningful optimized topologies of PnCs for the full frequency band and directional propagation with a broad frequency range is developed.

TL;DR: In this article, three kinds of novel two-dimensional enhanced star-shaped honeycombs (2D-ESSH) are proposed, which are consisted of the 2D-SSH and reinforcing rods.

TL;DR: In this paper, a constitutive model relating microstructural characteristics of hard-magnetic MAPs is proposed, which accounts for polymeric network pre-stretch, dipole-dipole interactions, Zeeman effect, and viscous mechanisms which are formulated on the finite deformation theory.

TL;DR: In this article, a near-field electrohydrodynamic direct writing method was proposed to fabricate the PVDF/SWCNTs thin film of the piezoelectric pressure sensor.

TL;DR: In this article, the authors proposed a method of creating geometrically reconfigurable and mechanically tunable multi-stable metamaterials to realize a kind of tunable elastic metammaterial with a stable state during the active regulation without continuous-consuming energy based on 4D printing technology.

TL;DR: This study presents a critical review of the literature along with descriptive appendices including images, brief descriptions, and video references of the most relevant magnetically actuated soft robots and electromagnets to act as a benchmark for the researchers who aim to conduct further research in this field.

TL;DR: A bistability-based foldable waterbomb origami consisting of bistable kirigami units is proposed, illustrating a possible solution for more complex logic operations from a mechanical deformation point of view by combining the logic gates together in a desired manner.

TL;DR: In this article, a multimaterial direct 4D printing method was proposed to fabricate patterned laminate that consists of covalently bonded elastomer and high-water-content hydrogel.

TL;DR: In this article, a novel lattice structure for energy absorption application is proposed that is modified from the traditional face-centered cubic (FCC) lattice by introducing a cross-rod at the center of the cell.

TL;DR: In this article, the authors demonstrate an approach to fabricating composite structures of magnetic hydrogels and elastomers with extrusion-based 3D printing, and achieve complex shape transformation of the composite structure.

TL;DR: In this paper, the fracture and fatigue of ideal polymer networks with controlled densities of dangling-chain defects were studied. And they showed that the fracture toughness and fatigue threshold of an ideal polymer network almost without defects are the same.

TL;DR: In this paper, a fatigue-resistant PU fiber-matrix composite, using commercially available Spandex as the fibers and PU elastomer as the matrix, is presented.

TL;DR: In this paper, the authors designed a double-elliptic-ring structure with tunable Poisson's ratio and Young's modulus, which can be used to construct 3D auxetic metamaterials with excellent properties.

TL;DR: A novel theoretical model V-Q-a based on contact-separation TENGs is proposed to systematically illuminate the mechanism of the self-powered acceleration sensor under different motion to effectively guide for optimizing sensor structure and performance in future specific applications.

TL;DR: Wang et al. as mentioned in this paper reported an approach for switchable adhesion between hydrogels by invoking a mechanical process, wrinkling, and demonstrated by bonding two hydrogel adherends with a wrinkled hyrogel adhesive, with the formation and characterizations of wrinkles tailored by regulating the prestretch of adherend and optimizing the ingredients of adhesive synergistically.

TL;DR: In this article, the authors investigate how the design of micro-scale pantographic structures can be circumvented through the use of microscale Pantographs, which possess riveting hyperelastic response inherited by their structural design, providing exorbitant reversible deformations.

TL;DR: In this article, the motion of the ultra-stretchable film in the flow is illustrated as a coupling of vortex-induced elastic torsional deformation and pressure-driven galloping.

TL;DR: In this article, a hierarchical auxetic structure consisting of a porous medium in which a homogeneous matrix includes a rank-two set of cuts characterised by different scales is proposed, and the sixfold symmetry of the perforations makes the medium isotropic in the plane.

TL;DR: In this article, the volume shrinkage-induced distortion of DLP-printed parts was investigated by conducting experiments, theoretical modeling, and finite element analysis (FEA) simulations.

TL;DR: In this paper, a chiral edge state at the interface between two subwavelength opposite chiral phononic crystals achieving edge state's robustness higher than the design with the topological C 6v design was proposed.

TL;DR: In this paper, a compact acoustic meta-structure consisting of labyrinth resonators arranged around a central air passage was designed and fabricated to provide a promising route to design well-ventilated and simultaneously highly effective sound-proofing barriers allowing broadband (about one octave band) transmission loss up to almost 30dB in the range of 660-1200 Hz.

TL;DR: A class of programmable stiffness metastructures designed by patterning locally bistable dome units in structural element geometries that allows for multi-directional linear and nonlinear response programmability, while operating under different loading environments.

TL;DR: In this paper, a magnetically switchable soft suction gripper was proposed to apply both small and large forces for picking 3D objects without applying excessive contact forces on fragile objects.

TL;DR: In this paper, a quasi-perfect sound-absorbing metasurface in spiral shape form is proposed to obtain extraordinary underwater sound isolation, which meets the two conditions for perfect absorption, which are no transmission at the outlet and no reflection at the inlet.

TL;DR: In this article, the impact tests of multilayer polyurea/silicon-carbide (SiC) nanostructures using molecular dynamics (MD) were conducted.

TL;DR: In this article, the high strain rate impact effect and failure behavior of three-dimensional six-directional (3D6d) braided composites with different braiding angles are reported.

TL;DR: In this paper, the authors constructed a thermally induced deformation and stress field in the rod during its steady rolling, further enabling the prediction of its rolling speed at different conditions.