Hybrid nanomembranes for high power and high energy density supercapacitors and their yarn application

Ultrathin (thicknessnm) electrically conducting membranes can be used as electrodes for sensors, actuators, optical devices, fuel cells, scaffolds for assembling nanoparticles, and separation of biological macromolecules.1-6 Various approaches have been suggested for the fabrication of free-standing nanomembranes based on organic polymers and/or inorganic materials: spin-casting of films,7 layer-by-layer assembly of polyelectrolyte multilayers,8 cross-linking of self-assembled monolayers,9 and assembly of triblock copolymers.10,11 Loading materials such as gold nanoparticles12 or carbon nanotubes13 make membranes robust and electrically conductive. However, these methods are often time-consuming and have some limitations in terms of achievable electrical and electrochemical membrane performance as well as scale-up. Alternative approaches are needed for the preparation of mechanically robust, free-standing, conductive nanomembranes that could be easily manufactured

Relationship between nanotopographical alignment and stem cell fate with live imaging and shape analysis

The topography of a biomaterial regulates cellular interactions and determine stem cell fate. A complete understanding of how topographical properties affect cell behavior will allow the rational design of material surfaces that elicit specified biological functions once placed in the body. To this end, we fabricate substrates with aligned or randomly organized fibrous nanostructured topographies. Culturing adipose-derived stem cells (ASCs), we explore the dynamic relationship between the alignment of topography, cell shape and cell differentiation to osteogenic and myogenic lineages. We show aligned topographies differentiate cells towards a satellite cell muscle progenitor state - a distinct cell myogenic lineage responsible for postnatal growth and repair of muscle. We analyze cell shape between the different topographies, using fluorescent time-lapse imaging over 21 days. In contrast to previous work, this allows the direct measurement of cell shape at a given time rather than defining the morphology of the underlying topography and neglecting cell shape. We report quantitative metrics of the time-based morphological behaviors of cell shape in response to differing topographies. This analysis offers insights into the relationship between topography, cell shape and cell differentiation. Cells differentiating towards a myogenic fate on aligned topographies adopt a characteristic elongated shape as well as the alignment of cells

Relationship between nanotopographical alignment and stem cell fate with live imaging and shape analysis

The topography of a biomaterial regulates cellular interactions and determine stem cell fate. A complete understanding of how topographical properties affect cell behavior will allow the rational design of material surfaces that elicit specified biological functions once placed in the body. To this end, we fabricate substrates with aligned or randomly organized fibrous nanostructured topographies. Culturing adipose-derived stem cells (ASCs), we explore the dynamic relationship between the alignment of topography, cell shape and cell differentiation to osteogenic and myogenic lineages. We show aligned topographies differentiate cells towards a satellite cell muscle progenitor state - a distinct cell myogenic lineage responsible for postnatal growth and repair of muscle. We analyze cell shape between the different topographies, using fluorescent time-lapse imaging over 21 days. In contrast to previous work, this allows the direct measurement of cell shape at a given time rather than defining the morphology of the underlying topography and neglecting cell shape. We report quantitative metrics of the time-based morphological behaviors of cell shape in response to differing topographies. This analysis offers insights into the relationship between topography, cell shape and cell differentiation. Cells differentiating towards a myogenic fate on aligned topographies adopt a characteristic elongated shape as well as the alignment of cells

A Reel-Wound Carbon Nanotube Polarizer for Terahertz Frequencies

Utilizing highly oriented multiwalled carbon nanotube aerogel sheets, we fabricated micrometer-thick freestanding carbon nanotube (CNT) polarizers. Simple winding of nanotube sheets on a U-shaped polyethylene reel enabled rapid and reliable polarizer fabrication, bypassing lithography or chemical etching processes. With the remarkable extinction ratio reaching similar to 37 dB in the broad spectral range from 0.1 to 2.0 THz, combined with the extraordinary gravimetric mechanical strength of CNTs, and the dispersionless character of freestanding sheets, the commercialization prospects for our CNT terahertz polarizers appear attractive

Fabrication of Stretchable Copper Coated Carbon Nanotube Conductor for Non-Enzymatic Glucose Detection Electrode with Low Detection Limit and Selectivity

The increasing demand for wearable glucose sensing has stimulated growing interest in stretchable electrodes. The development of the electrode materials having large stretchability, low detection limit, and good selectivity is the key component for constructing high performance wearable glucose sensors. In this work, we presented fabrication of stretchable conductor based on the copper coated carbon nanotube sheath-core fiber, and its application as non-enzymatic electrode for glucose detection with high stretchability, low detection limit, and selectivity. The sheath-core fiber was fabricated by coating copper coated carbon nanotube on a pre-stretched rubber fiber core followed by release of pre-stretch, which had a hierarchically buckled structure. It showed a small resistance change as low as 27% as strain increasing from 0% to 500% strain, and a low resistance of 0.4 Ω·cm−1 at strain of 500%. This electrode showed linear glucose concentration detection in the range between 0.05 mM and 5 mM and good selectivity against sucrose, lactic acid, uric acid, acrylic acid in phosphate buffer saline solution, and showed stable signal in high salt concentration. The limit of detection (LOD) was 0.05 mM, for the range of 0.05–5 mM, the sensitivity is 46 mA·M−1. This electrode can withstand large strain of up to 60% with negligible influence on its performance

Regulation of morphogenesis and neural differentiation of human mesenchymal stem cells using carbon nanotube sheets

In order to successfully utilize stem cells for therapeutic applications in regenerative medicine, efficient differentiation into a specific cell lineage and guidance of axons in a desired direction is crucial. Here, we used aligned multi-walled carbon nanotube (MWCNT) sheets to differentiate human mesenchymal stem cells (hMSCs) into neural cells. Human MSCs present a preferential adhesion to aligned CNT sheets with longitudinal stretch parallel to the CNT orientation direction. Cell elongation was 2-fold higher than the control and most of the cells were aligned on CNT sheets within 51 from the CNT orientation direction. Furthermore, a significant, synergistic enhancement of neural differentiation was observed in hMSCs cultured on the CNT sheets. Axon outgrowth was also controlled using nanoscale patterning of CNTs. This CNT sheet provides a new cellular scaffold platform that can regulate morphogenesis and differentiation of stem cells, which could open up a new approach for tissue and stem cell regeneration.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000002410/9SEQ:9PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000002410ADJUST_YN:YEMP_ID:A002014DEPT_CD:458CITE_RATE:4.509FILENAME:Regulation of morphogenesis and neural differentiation of human.pdfDEPT_NM:화학생물공학부EMAIL:[email protected]_YN:NCONFIRM:YN

Electrical Stimulation of Myoblast Proliferation and Differentiation on Aligned Nanostructured Conductive Polymer Platforms

In this study, nanostructured conductive platforms synthesized from aligned multiwalled carbon nanotubes and polypyrrole are investigated as myo-regenerative scaffolds. Myotube formation follows a linear path on the platforms coinciding with extent of nanotopography. In addition, electrical stimulation enhances myo-nuclear number and differentiation. These studies demonstrate that conductive polymer platforms can be used to influence muscle cell behaviour through nanostructure and electrical stimulation