Materials with target nonlinear mechanical response can support the design of innovative soft robots, wearable devices, footwear, and energy-absorbing systems, yet it is challenging to realize them. Here, metamaterials based on hinged quadrilaterals are used as a platform responses. It first shown that by changing shape quadrilaterals, amount internal rotations induced applied compression be tuned, wide range responses achieved. Next, neural network introduced provides computationally...

Abstract Across fields of science, researchers have increasingly focused on designing soft devices that can shape‐morph to achieve functionality. However, identifying a rest shape leads target 3D upon actuation is non‐trivial task involves inverse design capabilities. In this study, simple and efficient platform presented pre‐programmed shapes starting from 2D planar composite membranes. By training neural networks with small set finite element simulations, the authors are able obtain both...

Abstract Physics-based deep learning frameworks have shown to be effective in accurately modeling the dynamics of complex physical systems with generalization capability across problem inputs. However, time-independent problems pose challenge requiring long-range exchange information computational domain for obtaining accurate predictions. In context graph neural networks (GNNs), this calls deeper networks, which, turn, may compromise or slow down training process. work, we present two GNN...

A significant challenge in flexural wave energy harvesting is the design of an aberration-free lens capable finely focusing waves over a broad frequency range. To date, lenses have been created using discrete inclusions, voids, or stubs, often periodic arrangement, to focus via scattering. These structures are narrowband either because scattering efficient small range arrangements exploit Bragg bandgaps, which themselves narrowband. In addition, current designs based on single and...

Significance From foldable chairs and umbrellas to tents solar panels, many structures are capable of quickly changing their shape therefore, function. The design these deployable poses two main challenges. First, transformation needs be reliable autonomous, second, systems have stable locked in place the deployed state. Using a combination experiments analyses, we demonstrate that bistable linkages transition waves provide powerful platform for realizing structures. We first carefully...

A major obstacle in designing a perfect cloak for objects shallow-water waves is that the linear transformation media scheme (also known as optics) requires spatial variations of two independent medium properties. In Maxwell’s equation and well-studied problem electromagnetic cloaking, these properties are permittivity permeability. Designing an anisotropic material with both variable permeability, while challenging, achievable. On other hand, long gravity waves, whose governing maps...

Broadband cloaking of flexural waves is a major challenge since the governing equation not form invariant under coordinate transformations. We fabricate structure using only single material composed homogeneous and isotropic layers, then present experimental evidence first near-ideal broadband cloak in thin plates. The 3D-printed shown to effectively disguise an object over broad frequency range (2 kHz-11 kHz). proposed has potential applications shielding sensors sensitive components from...

Abstract Inspired by the recent success of buckling‐induced reconfigurable structures, a new class deployable systems that harness buckling curved beams upon rotational input is proposed. First, experimental and numerical methods are combined to investigate influence beam's geometric parameters on its non‐linear response. Then, it shown wide range architectures can be realized combining beams. Finally, proposed principles used build furniture such as tables lamp shades flat/compact for...

The governing equation for elastic waves in flexural plates is not form invariant, and hence designing a cloak such faces major challenge. Here, we present the design of perfect broadband through use nonlinear transformation region by matching term original transformed equations also assuming prestressed material with body forces. For readily achievable physical setting, further an approximate adoption our under more restrictive constraints. Through direct simulation equations, show that...

Directing and controlling flexural waves in thin plates along a curved trajectory over broad frequency range is significant challenge that has various applications imaging, cloaking, wave focusing, wireless power transfer circumventing obstacles. To date, all studies appeared elastic structures using periodic arrays of inclusions where these are narrowband either because scattering efficient small range, or the arrangements exploit Bragg bandgaps, which themselves narrowband. Here, we design...

The trajectory of surface gravity waves in the potential flow regime is affected by gravitational acceleration, water density and sea bed depth. Although acceleration are approximately constant, effect depth on exponentially decreases as increases. In shallow water, cloaking an object from varying topography possible, however, increases, becomes a challenge because there no physical parameter to be engineered subsequently affects wave propagation. order create omnidirectional cylindrical...

Programming physical intelligence into mechanisms holds great promise for machines that can accomplish tasks such as navigation of unstructured environments while utilizing a minimal amount computational resources and electronic components. In this study, we introduce novel design approach physically intelligent under-actuated capable autonomously adjusting their motion in response to environmental interactions. Specifically, multistability is harnessed sequence the different degrees freedom...

Physics-based deep learning frameworks have shown to be effective in accurately modeling the dynamics of complex physical systems with generalization capability across problem inputs. However, time-independent problems pose challenge requiring long-range exchange information computational domain for obtaining accurate predictions. In context graph neural networks (GNNs), this calls deeper networks, which, turn, may compromise or slow down training process. work, we present two GNN...

Abstract The substantial deformation exhibited by hyperelastic cylindrical shells under pressurization makes them an ideal platform for programmable inflatable structures. If negative pressure is applied, the shell will buckle, leading to a sequence of rich modes, all which are fully recoverable due material choice. While initial buckling event vacuum well understood, here, post‐buckling regime explored and region in design space identified coupled twisting‐contraction mode occurs; carefully...

We study the dynamics of flow networks in porous media using two and three dimensional pore-network models. consider a class erosion for single phase with no deposition, chemical reactions, or topology changes assuming constitutive law depending on rate, local velocities, shear stress at walls. show that law, may become uniform homogenized unstable develop channels. By defining an order parameter capturing these different behaviors we transition occurs dynamics. Using simple model, identify...

Here we show that there exist internal gravity waves are inherently unstable, is, they cannot in nature for a long time. The instability mechanism is one-way (irreversible) harmonic-generation resonance permanently transfers the energy of an wave to its higher harmonics. We that, fact, countably infinite number such unstable waves. For take place, nonlinear terms free surface boundary condition play pivotal role, and does not obtain linearly-stratified fluid if simplified as rigid lid or...

Flow and retention of polymer in porous media result an unexpected reduction medium permeability. Our experiment simulation show that these changes are a direct consequence pore blockage diversion flow through the medium. Despite complex after retention, we introduce simple scaling for distribution pore-level velocities based on bulk permeability

One of the main challenges in solving time-dependent partial differential equations is to develop computationally efficient solvers that are accurate and stable. Here, we introduce a graph neural network approach finding PDE through learning using message-passing models. We first domain invariant features for PDE-data inspired by classical an physical representation. Next, use graphs represent on unstructured mesh show message passing networks (MPGNN) can parameterize governing equations, as...

Mechanical deformation has recently emerged as a promising platform to realize optical devices with tunable response. While most studies date have focused on the tuning of focal length, here we use combination experiments and analyses show that an applied tensile strain can also largely reduce spherical aberration. We first demonstrate concept for cylindrical elastomeric lens then it is robust valid over range geometries material properties. As such, our study suggests large mechanical...

Here we show that the distribution of energy internal gravity waves over a patch seabed corrugations strongly depends on distance to adjacent seafloor features located downstream patch. Specifically, consider steady state due an incident wave arriving at ripples neighbouring (i) another (i.e. second patch) and (ii) vertical wall. Seabed undulations with dominant wavenumber twice as large overpassing reflect back part (Bragg reflection) allow rest transmit downstream. In presence topography...

Breaking reciprocity has recently gained significant attention due to its broad range of applications in engineering systems. Here, we introduce the first experimental demonstration a broadband mechanical beam waveguide, which can be reconfigured represent wave nonreciprocity. This is achieved by using spatiotemporal stiffness modulation with piezoelectric patches closed-loop controller. Using combination analytical methods, numerical simulations, and measurements, show that contrary...

Naturally inspired: For propulsion and mixing under conditions of low Reynolds number, one could replicate the locomotion microorganisms that have evolved to swim in highly viscous environments. Thus authors simulate motion head segment $C.$ $e\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}s$ roundworm with a reciprocating rocking blade. The biomimetic blade chaotically mixes surrounding fluid via...