@article{13375, abstract = {Dissipative self-assembly leads to structures and materials that exist away from equilibrium by continuously exchanging energy and materials with the external environment. Although this mode of self-assembly is ubiquitous in nature, where it gives rise to functions such as signal processing, motility, self-healing, self-replication, and ultimately life, examples of dissipative self-assembly processes in man-made systems are few and far between. Herein, recent progress in developing diverse synthetic dissipative self-assembly systems is discussed. The systems reported thus far can be categorized into three classes, in which: i) the fuel chemically modifies the building blocks, thus triggering their self-assembly, ii) the fuel acts as a template interacting with the building blocks noncovalently, and iii) transient states are induced by the addition of two mutually exclusive stimuli. These early studies give rise to materials that would be difficult to obtain otherwise, including hydrogels with programmable lifetimes, vesicular nanoreactors, and membranes exhibiting transient conductivity.}, author = {De, Soumen and Klajn, Rafal}, issn = {1521-4095}, journal = {Advanced Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, General Materials Science}, number = {41}, publisher = {Wiley}, title = {{Dissipative self-assembly driven by the consumption of chemical fuels}}, doi = {10.1002/adma.201706750}, volume = {30}, year = {2018}, } @article{10359, abstract = {Biological membranes typically contain a large number of different components dispersed in small concentrations in the main membrane phase, including proteins, sugars, and lipids of varying geometrical properties. Most of these components do not bind the cargo. Here, we show that such “inert” components can be crucial for the precise control of cross-membrane trafficking. Using a statistical mechanics model and molecular dynamics simulations, we demonstrate that the presence of inert membrane components of small isotropic curvatures dramatically influences cargo endocytosis, even if the total spontaneous curvature of such a membrane remains unchanged. Curved lipids, such as cholesterol, as well as asymmetrically included proteins and tethered sugars can, therefore, actively participate in the control of the membrane trafficking of nanoscopic cargo. We find that even a low-level expression of curved inert membrane components can determine the membrane selectivity toward the cargo size and can be used to selectively target membranes of certain compositions. Our results suggest a robust and general method of controlling cargo trafficking by adjusting the membrane composition without needing to alter the concentration of receptors or the average membrane curvature. This study indicates that cells can prepare for any trafficking event by incorporating curved inert components in either of the membrane leaflets.}, author = {Curk, Tine and Wirnsberger, Peter and Dobnikar, Jure and Frenkel, Daan and Šarić, Anđela}, issn = {1530-6992}, journal = {Nano Letters}, keywords = {mechanical engineering, condensed matter physics}, number = {9}, pages = {5350--5356}, publisher = {American Chemical Society}, title = {{Controlling cargo trafficking in multicomponent membranes}}, doi = {10.1021/acs.nanolett.8b00786}, volume = {18}, year = {2018}, } @article{13406, abstract = {Dual-responsive nanoparticles are designed by functionalizing magnetic cores with light-responsive ligands. These materials respond to both light and magnetic fields and can be assembled into various higher-order structures, depending on the relative contributions of these two stimuli.}, author = {Das, Sanjib and Ranjan, Priyadarshi and Maiti, Pradipta Sankar and Singh, Gurvinder and Leitus, Gregory and Klajn, Rafal}, issn = {0935-9648}, journal = {Advanced Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, General Materials Science}, number = {3}, pages = {422--426}, publisher = {Wiley}, title = {{Dual-responsive nanoparticles and their self-assembly}}, doi = {10.1002/adma.201201734}, volume = {25}, year = {2013}, } @article{13416, abstract = {The reversible molecular template-directed self-assembly of gold nanoparticles (AuNPs), a process which relies solely on noncovalent bonding interactions, has been demonstrated by high-resolution transmission electron microscopy (HR-TEM). By employing a well-known host−guest binding motif, the AuNPs have been systemized into discrete dimers, trimers, and tetramers. These nanoparticulate twins, triplets, and quadruplets, which can be disassembled and reassembled either chemically or electrochemically, can be coalesced into larger, permanent polygonal structures by thermal treatment using a focused HR-TEM electron beam.}, author = {Olson, Mark A. and Coskun, Ali and Klajn, Rafal and Fang, Lei and Dey, Sanjeev K. and Browne, Kevin P. and Grzybowski, Bartosz A. and Stoddart, J. Fraser}, issn = {1530-6992}, journal = {Nano Letters}, keywords = {Mechanical Engineering, Condensed Matter Physics, General Materials Science, General Chemistry, Bioengineering}, number = {9}, pages = {3185--3190}, publisher = {American Chemical Society}, title = {{Assembly of polygonal nanoparticle clusters directed by reversible noncovalent bonding interactions}}, doi = {10.1021/nl901385c}, volume = {9}, year = {2009}, } @article{13419, abstract = {Reaction-diffusion (RD) processes initiated from the surfaces of mesoscopic particles can fabricate complex core-and-shell structures. The propagation of a sharp RD front selectively removes metal colloids or nanoparticles from the supporting gel or polymer matrix. Once fabricated, the core structures can be processed “remotely” via galvanic replacement reactions, and the composite particles can be assembled into open-lattice crystals.}, author = {Wesson, Paul J. and Soh, Siowling and Klajn, Rafal and Bishop, Kyle J. M. and Gray, Timothy P. and Grzybowski, Bartosz A.}, issn = {1521-4095}, journal = {Advanced Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, General Materials Science}, number = {19}, pages = {1911--1915}, publisher = {Wiley}, title = {{“Remote” fabrication via three-dimensional reaction-diffusion: Making complex core-and-shell particles and assembling them into open-lattice crystals}}, doi = {10.1002/adma.200802964}, volume = {21}, year = {2009}, } @article{9149, abstract = {The interaction of tidal currents with sea-floor topography results in the radiation of internal gravity waves into the ocean interior. These waves are called internal tides and their dissipation due to nonlinear wave breaking and concomitant three-dimensional turbulence could play an important role in the mixing of the abyssal ocean, and hence in controlling the large-scale ocean circulation. As part of on-going work aimed at providing a theory for the vertical distribution of wave breaking over sea-floor topography, in this paper we investigate the instability of internal tides in a very simple linear model that helps us to relate the formation of unstable regions to simple features in the sea-floor topography. For two-dimensional tides over one-dimensional topography we find that the formation of overturning instabilities is closely linked to the singularities in the topography shape and that it is possible to have stable waves at the sea floor and unstable waves in the ocean interior above. For three-dimensional tides over two-dimensional topography there is in addition an effect of geometric focusing of wave energy into localized regions of high wave amplitude, and we investigate this focusing effect in simple examples. Overall, we find that the distribution of unstable wave breaking regions can be highly non-uniform even for very simple idealized topography shapes.}, author = {Bühler, Oliver and Muller, Caroline J}, issn = {0022-1120}, journal = {Journal of Fluid Mechanics}, keywords = {mechanical engineering, mechanics of materials, condensed matter physics}, pages = {1--28}, publisher = {Cambridge University Press}, title = {{Instability and focusing of internal tides in the deep ocean}}, doi = {10.1017/s0022112007007410}, volume = {588}, year = {2007}, } @article{13431, abstract = {Hydrogel stamps can microstructure solid surfaces, i.e., modify the surface topology of metals, glasses, and crystals. It is demonstrated that stamps soaked in an appropriate etchant can remove material with micrometer-scale precision. The Figure shows an array of concentric circles etched in glass using the immersion wet stamping process described (scale bar: 500 μm).}, author = {Smoukov, S. K. and Bishop, K. J. M. and Klajn, Rafal and Campbell, C. J. and Grzybowski, B. A.}, issn = {1521-4095}, journal = {Advanced Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, General Materials Science}, number = {11}, pages = {1361--1365}, publisher = {Wiley}, title = {{Cutting into solids with micropatterned gels}}, doi = {10.1002/adma.200402086}, volume = {17}, year = {2005}, } @article{13434, abstract = {Thin films of ionically doped gelatin have been color-patterned with submicrometer precision using the wet-stamping technique. Inorganic salts are delivered onto the gelatin surface from an agarose stamp, and diffuse into the gelatine layer, producting deeply colored precipitates. Reaction fronts originating from different features of the stamp cease within < 1 μm of each other, leaving sharp, transparent regions in between.}, author = {Campbell, C. J. and Fialkowski, M. and Klajn, Rafal and Bensemann, I. T. and Grzybowski, B. A.}, issn = {1521-4095}, journal = {Advanced Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, General Materials Science}, number = {21}, pages = {1912--1917}, publisher = {Wiley}, title = {{Color micro- and nanopatterning with counter-propagating reaction-diffusion fronts}}, doi = {10.1002/adma.200400383}, volume = {16}, year = {2004}, } @article{13435, abstract = {Micropatterning of surfaces with several chemicals at different spatial locations usually requires multiple stamping and registration steps. Here, we describe an experimental method based on reaction–diffusion phenomena that allows for simultaneous micropatterning of a substrate with several coloured chemicals. In this method, called wet stamping (WETS), aqueous solutions of two or more inorganic salts are delivered onto a film of dry, ionically doped gelatin from an agarose stamp patterned in bas relief. Once in conformal contact, these salts diffuse into the gelatin, where they react to give deeply coloured precipitates. Separation of colours in the plane of the surface is the consequence of the differences in the diffusion coefficients, the solubility products, and the amounts of different salts delivered from the stamp, and is faithfully reproduced by a theoretical model based on a system of reaction–diffusion partial differential equations. The multicolour micropatterns are useful as non-binary optical elements, and could potentially form the basis of new applications in microseparations and in controlled delivery.}, author = {Klajn, Rafal and Fialkowski, Marcin and Bensemann, Igor T. and Bitner, Agnieszka and Campbell, C. J. and Bishop, Kyle and Smoukov, Stoyan and Grzybowski, Bartosz A.}, issn = {1476-4660}, journal = {Nature Materials}, keywords = {Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science, General Chemistry}, pages = {729--735}, publisher = {Springer Nature}, title = {{Multicolour micropatterning of thin films of dry gels}}, doi = {10.1038/nmat1231}, volume = {3}, year = {2004}, }