Organic solar cells

Photonic Color Filters Integrated with Organic Solar Cells for Energy Harvesting

Hui Joon Park†, Ting Xu‡

, Jae Yong Lee‡, Abram Ledbetter

, and L. Jay Guo†‡

^†Macromolecular Science and Engineering, ^‡Electrical Engineering and Computer Science, Applied Physics,The University of Michigan, Ann Arbor, Michigan 48109, United States, and Institute of Optics and Electronics,Chinese Academy of Sciences, Chengdu, 610209, China.

ACS Nano, 2011, 5 (9), pp 7055–7060

DOI: 10.1021/nn201767e

Publication Date (Web): July 31, 2011

Color filters are indispensable in most color display applications. In most cases, they are chemical pigment-based filters, which produce a particular color by absorbing its complementary color, and the absorbed energy is totally wasted. If the absorbed and wasted energy can be utilized, e.g., to generate electricity, innovative energy-efficient electronic media could be envisioned. Here we show photonic nanostructures incorporated with photovoltaics capable of producing desirable colors in the visible band and utilize the absorbed light to simultaneously generate electrical powers. In contrast to the traditional colorant-based filters, these devices offer great advantages for electro-optic applications.

Nanobattery and nanomotor together (jacs article will cool videos)

Autonomous Nanomotor Based on Copper–Platinum Segmented Nanobattery

Ran Liu and Ayusman Sen*

Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States

J. Am. Chem. Soc., Article ASAP

DOI: 10.1021/ja2082735

Publication Date (Web): September 30, 2011

We describe an efficient, bubble-free nanoscale motor consisting of a copper–platinum (Cu–Pt) segmented rod that operates as a nanobattery in dilute aqueous Br₂ or I₂ solutions. The motion of the rod is powered by self-electrophoresis caused by redox reactions occurring on the two different metal segments. Asymmetric ratchet-shaped pure copper nanorods were also found to rotate and tumble in aqueous Br₂ solution because of the ion gradient arising from asymmetric dissolution of copper.

Giant Unilamellar esicles meeting together

Membrane Protrusion Coarsening and Nanotubulation within Giant Unilamellar Vesicles

Ilona Węgrzyn†, Gavin D. M. Jeffries†, Birgit Nagel‡, Martin Katterle‡, Simon R. Gerrard§, Tom Brown§, Owe Orwar†, and Aldo Jesorka*†
J. Am. Chem. Soc., Article ASAP

DOI: 10.1021/ja207536a

Publication Date (Web): October 6, 2011

Hydrophobic side groups on a stimuli-responsive polymer, encapsulated within a single giant unilamellar vesicle, enable membrane attachment during compartment formation at elevated temperatures. We thermally modulated the vesicle through implementation of an IR laser via an optical fiber, enabling localized directed heating. Polymer–membrane interactions were monitored using confocal imaging techniques as subsequent membrane protrusions occurred and lipid nanotubes formed in response to the polymer hydrogel contraction. These nanotubes, bridging the vesicle membrane to the contracting hydrogel, were retained on the surface of the polymer compartment, where they were transformed into smaller vesicles in a process reminiscent of cellular endocytosis. This development of a synthetic vesicle system containing a stimuli-responsive polymer could lead to a new platform for studying inter/intramembrane transport through lipid nanotubes.

An electronic tattoo that monitors our body activities (Science article by John Rogers)

Epidermal Electronics

Science 12 August 2011:
Vol. 333 no. 6044 pp. 838-843
DOI: 10.1126/science.1206157

ABSTRACT

An electronic tattoo sticking on to skin

We report classes of electronic systems that achieve thicknesses, effective elastic moduli, bending stiffnesses, and areal mass densities matched to the epidermis. Unlike traditional wafer-based technologies, laminating such devices onto the skin leads to conformal contact and adequate adhesion based on van der Waals interactions alone, in a manner that is mechanically invisible to the user. We describe systems incorporating electrophysiological, temperature, and strain sensors, as well as transistors, light-emitting diodes, photodetectors, radio frequency inductors, capacitors, oscillators, and rectifying diodes. Solar cells and wireless coils provide options for power supply. We used this type of technology to measure electrical activity produced by the heart, brain, and skeletal muscles and show that the resulting data contain sufficient information for an unusual type of computer game controller.

Nature article on "Breaking the diffraction barrier"

Diffraction-unlimited all-optical imaging and writing with a photochromic GFP

Nature 478, 204–208 (13 October 2011)

Lens-based optical microscopy failed to discern fluorescent features closer than 200 nm for decades, but the recent breaking of the diffraction resolution barrier by sequentially switching the fluorescence capability of adjacent features on and off is making nanoscale imaging routine. Reported fluorescence nanoscopy variants switch these features either with intense beams at defined positions or randomly, molecule by molecule. Here we demonstrate an optical nanoscopy that records raw data images from living cells and tissues with low levels of light. This advance has been facilitated by the generation of reversibly switchable enhanced green fluorescent protein (rsEGFP), a fluorescent protein that can be reversibly photoswitched more than a thousand times. Distributions of functional rsEGFP-fusion proteins in living bacteria and mammalian cells are imaged at <40-nanometre resolution. Dendritic spines in living brain slices are super-resolved with about a million times lower light intensities than before. The reversible switching also enables all-optical writing of features with subdiffraction size and spacings, which can be used for data storage.