Folding Paper-Based Lithium-Ion Batteries for Higher Areal Energy Densities

Qian Cheng †, Zeming Song †, Teng Ma ‡, Bethany B. Smith †, Rui Tang §, Hongyu Yu §, Hanqing Jiang ‡, and Candace K. Chan *†

Nano Lett., 2013, 13 (10), pp 4969–4974
DOI: 10.1021/nl4030374
Publication Date (Web): September 23, 2013
Copyright © 2013 American Chemical Society

Paper folding techniques are used in order to compact a Li-ion battery and increase its energy per footprint area. Full cells were prepared using Li4Ti5O12 and LiCoO2 powders deposited onto current collectors consisting of paper coated with carbon nanotubes. Folded cells showed higher areal capacities compared to the planar versions with a 5 × 5 cell folded using the Miura-ori pattern displaying a 14× increase in areal energy density.

Lithographically Defined Macroscale Modulation of Lateral Fluidity and Phase Separation Realized via Patterned Nanoporous Silica-Supported Phospholipid Bilayers

Eric L. Kendall †, Viviane N. Ngassam ‡, Sean F. Gilmore §, C. Jeffrey Brinker , and Atul N. Parikh *†‡§


J. Am. Chem. Soc., Article ASAP
DOI: 10.1021/ja408434r
Publication Date (Web): October 10, 2013
Copyright © 2013 American Chemical Society

Using lithographically defined surfaces consisting of hydrophilic patterns of nanoporous and nonporous (bulk) amorphous silica, we show that fusion of small, unilamellar lipid vesicles produces a single, contiguous, fluid bilayer phase experiencing a predetermined pattern of interfacial interactions. Although long-range lateral fluidity of the bilayer, characterized by fluorescence recovery after photobleaching, indicates a nominally single average diffusion constant, fluorescence microscopy-based measurements of temperature-dependent onset of fluidity reveals a locally enhanced fluidity for bilayer regions supported on nanoporous silica in the vicinity of the fluid–gel transition temperature. Furthermore, thermally quenching lipid bilayers composed of a binary lipid mixture below its apparent miscibility transition temperature induces qualitatively different lateral phase separation in each region of the supported bilayer: The nanoporous substrate produces large, microscopic domains (and domain-aggregates), whereas surface texture characterized by much smaller domains and devoid of any domain-aggregates appears on bulk glass-supported regions of the single-lipid bilayer. Interestingly, lateral distribution of the constituent molecules also reveals an enrichment of gel-phase lipids over nanoporous regions, presumably as a consequence of differential mobilities of constituent lipids across the topographic bulk/nanoporous boundary. Together, these results reveal that subtle local variations in constraints imposed at the bilayer interface, such as by spatial variations in roughness and substrate adhesion, can give rise to significant differences in macroscale biophysical properties of phospholipid bilayers even within a single, contiguous phase.

Villification: How the Gut Gets Its Villi

Amy E. Shyer1,*, Tuomas Tallinen2,3,*, Nandan L. Nerurkar1, Zhiyan Wei2, Eun Seok Gil4, David L. Kaplan4, Clifford J. Tabin1,†, L. Mahadevan2,5,6,7,8,†

Published Online August 29 2013Science 11 October 2013: 
Vol. 342 no. 6155 pp. 212-218 
DOI: 10.1126/science.1238842

The villi of the human and chick gut are formed in similar stepwise progressions, wherein the mesenchyme and attached epithelium first fold into longitudinal ridges, then a zigzag pattern, and lastly individual villi. We find that these steps of villification depend on the sequential differentiation of the distinct smooth muscle layers of the gut, which restrict the expansion of the growing endoderm and mesenchyme, generating compressive stresses that lead to their buckling and folding. A quantitative computational model, incorporating measured properties of the developing gut, recapitulates the morphological patterns seen during villification in a variety of species. These results provide a mechanistic understanding of the formation of these elaborations of the lining of the gut, essential for providing sufficient surface area for nutrient absorption.