Ultrathin Hydrogen Diffusion Cloak

Abstract

For years, hydrogen damage is a fatal threat to metals and alloys in long-term service. This paper introduces the transformation optics theory in metamaterials to the diffusive field, and the design of an ultrathin hydrogen diffusion cloak. Thanks to the alternately and gradually changed diffusion coefficients in adjacent layers, the laminated cloak efficiently conducts the diffusive flow to shield the central region, and drastically reduces the diffusion flux in it. More importantly, the diffusion coefficients are designed following the Laplace equation instead of conventional linear transformation, hence the cloak has a very small thickness whose core/shell ratio is two magnitudes larger than traditional designs, but the diffusion flux is even one magnitude lower. The ultrathin hydrogen diffusion cloak with excellent performance provides a promising route for hydrogen protection.

Chemical-diffusion Metamaterials with “Plug and Switch” Modules for Ion Cloaking, Concentrating and Selection: Design and Experiments

“…In addition to the ideal cloaking proposed by theory and demonstrated by experiments, the design is further extended to metamaterials with diversified functions such as concentrators 3,4 , rotators 5,6 and illusion metamaterials 7,8 . After great success in manipulating electromagnetic waves [9][10][11] , TO and SC were also proven to be powerful tools to manipulate not only other wave-based fields like acoustic waves [12][13][14] and water waves 15,16 but also diffusion fields such as thermal flux [17][18][19][20][21][22][23][24][25] , electric fields [26][27][28][29] , magnetic fields [30][31][32][33][34] , diffusive light [35][36][37] and chemical fields [38][39][40][41][42][43] . For comparison, metamaterials designed by TO usually exhibit substantial inhomogeneity and anisotropy, while SC provides a simpler way to achieve cloaking for diffusion fields by obeying the Laplacian equation, i.e., Laplacian fields.…”

“…For years, researchers have devoted their efforts to seeking a more effective method to control the behavior of diffusion for applications in chemical and biological engineering. Although the idea of manipulating chemical flow by metamaterials has been proposed for years 40,41 , related research is still rare [38][39][40][41][42][43] . In particular, most studies are limited to theoretical design and numerical simulation rather than experiments, and those that do involve experimentation deal only with the tractable solid samples instead of the more general liquid environments.…”

Scattering Cancellation by a Monolayer Cloak in Oxide Dispersion‐Strengthened Alloys

“…After great success in the electromagnetic field, [12][13][14] the cloak design has been extended to multiple physical fields, not only wave-based fields [15][16][17][18][19][20] but also diffusion fields, [21][22][23] including heat [24][25][26][27][28][29][30][31][32][33][34][35][36][37] or matter diffusion. [38][39][40][41][42][43][44][45][46][47] Regarding a cloak for matter flow, Cui et al designed a multilayer structure of an equivalent resistor network with anisotropic conductivity based on transformation optics to effectively control the direct current (DC) electron flow bypassing the central region; this structure avoids the interaction between the central region and the external field distribution. [44] Moreover, Qiu et al designed a bilayer cloak made of bulk natural materials through the scattering cancellation method, which demonstrates the successful manipulation of DC currents by such a simple structure in a 2D scenario.…”

Simulation Assisted Nanoscale Imaging of Single Live Cells with Scanning Electrochemical Microscopy

“…SECM scans are often coupled with finite element method (FEM) simulations to provide additional quantification of sample features . FEM has been proven to be very useful in metamaterials, energy materials and devices, and nanogenerators …”