2.19.2008

Muscular thin films



Muscle cells from rat were cultured on thin films of polydimethylsiloxane. The alignment of the resulting muscles was achieved by culturing the cells on patterned surfaces. The muscular thin films were released and shown to perform tasks typical of muscle tissues. This simple system offers an alternative to designing actuators and powering devices.

The image shows a thin anisotropic myocardium that brings the tips together upon contraction. Scale bar = 1 mm.

Feinberg A.W. et al.; Muscular Thin Films for Building Actuators and Powering Devices. Science 317: 1366 - 1370 (2007).

Gecko-inspired bandages



Langer's team was inspired by the nanoscopic morphology of gecko's feet while developing a new generation of medical adhesives that can adapt to or recover from various mechanical deformations while remaining strongly attached to the underlying tissue. Surfaces molded in polymer poly(glycerol-co-sebacate acrylate) mimicking nanotopography of gecko feet offer biocompatibility, biodegradation, strong adhesive tissue bonding, as well as compliance and conformability to tissue surfaces. Adding a thin layer of dextran significantly increased the strength of adhesion. And in future work is planned to include an ability to deliver drugs or growth factors to promote healing.

The image is scanning electron micrograph showing how the microscopic features remain preserved on the surface even after an extended time in physiological conditions that cause the bandage to degrade. Scale bar = 10 um.

More info:
more about gecko's feet...

Mahdavi A. et al.; A biodegradable and biocompatible gecko-inspired tissue adhesive. Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0712117105.

2.01.2008

Cradle to Cradle



Authors: William McDonough and Michael Braungart
Paperback: 208 pages
Publisher: North Point Press; 1 edition (April 22, 2002)

In Cradle to Cradle, McDonough and Braungart argue that the conflict between industry and the environment is not an indictment of commerce but an outgrowth of purely opportunistic design. The design of products and manufacturing systems growing out of the Industrial Revolution reflected the spirit of the day - and yielded a host of unintended yet tragic consequences.

Author's website | Buy on Amazon

1.07.2008

Eduardo Kac and fluorescent bunny



Eduardo Kac's "GFP Bunny" was born in 2000 and first presented publicly in Avignon, France. According to Kac, "transgenic art is a new art form based on the use of genetic engineering to transfer natural or synthetic genes to an organism, to create unique living beings. This must be done with great care, with acknowledgment of the complex issues thus raised and, above all, with a commitment to respect, nurture, and love the life thus created".

More information:
Artist's website

1.06.2008

Non-stick shark skin



Until recently, preventing the adhesion of marine organisms to ship hulls and underwater structures meant using biocide-containing paints that have shown only limited success, short lifetime and dangerous toxic effects on environment. A completely new approach mimics the design of shark skin that consists of tightly packed scales with microscopic ridges (large image - scanning electron micrograph). The combination of the movement of the scales relative to each other and minimal contact area with any adhered organisms eliminates biofouling on shark's skin. Ralph Liedert from the University of Applied Sciences, Bremen, Germany, has created a microfabricated simplified version of this surface (inset on the left) that resulted in self-cleaning at small fluid velocities and prevented the most of the adhering organisms to remain attached (center inset is a control surface compared to microfabricated surface on the right).

More info:

Fake Shark Skin Could Make Navy Fleet Faster
by Robert Roy Britt, LiveScience.com (July 15, 2005)

Images from The Electron Microscopy Unit at the University of Cape Town and University of Applied Sciences in Bremen. The length-scale bars correspond to ~200 um.

1.04.2008

Bacteria produce hydrogen from grass clippings



Researchers at Penn State University have harnessed the ability of bacteria to extract hydrogen from almost any biodegradable organic substance that is usually discarded as waste. This efficient process is a great alternative to the current way of producing hydrogen from natural gas. The method produces up to 82 percent more energy than the the input energy needed to produce it, which is almost three times more than corn-based ethanol.

More information:
Cheng, S. and Logan, B.E.; Sustainable and efficient biohydrogen production via electrohydrogenesis. PNAS 104(47): 18871-18873 (2007).

New story in Wired Magazine. A great overview of current research in area of microbial fuel cells is at microbialfuelcell.org.

Moss Graffiti



Moss is a wonderful alternative to paint or even spray paint. The recipe is so simple that anyone can prepare this "paint" in their kitchen or classroom. And apparently moss will colonize and grow on any moist surface.

Art by Helen Nodding and Edina Tokodi.

Biomimicry: Innovation Inspired by Nature



Author: Janine M. Benyus
Paperback: 320 pages
Publisher: Harper Perennial (September 17, 2002)

The sophisticated, almost pro-growth angle of Benyus shows the great potential profitability of copying some of nature's time-tested, nonpolluting, room-temperature manufacturing and computing technologies. Read the rest of the review in NY Times...

Video: 12 sustainable design ideas from nature | Buy on Amazon

1.03.2008

Biomimetic mobile microrobots



Robert Wood began working on a robotic fly as a graduate student at the University of California, Berkeley in the late 1990s. Now as an assistant professor at the Harvard University and supported by funding from the Defense Advanced Research Projects Agency he has been improving the robotic fly whose eventual applications might include rescue operations and surveillance. Though still missing an autonomous power source and a control unit, the fly is an elegant example of biomimetic design.

Wood’s other efforts to replicate nature include also a robotic minnow-sized fish, a cockroach-sized crawling robot, and even a hummingbird.

Website of Robert Wood (Harvard U)
Video of the robotic fly (from Harvard Magazine)

12.12.2007

Blue Morph



Blue Morph is an interactive installation that uses nanoscale images and sounds derived from the metamorphosis of a caterpillar into a butterfly developed by Victoria Vesna at UCLA.

Exhibit website
Studio 360 Interview

11.08.2007

Remotely controlled genes



Researchers at MIT have developed a remote control for turning certain genes on and off. They achieved it by binding a nanoscopic gold particle to a section of DNA. In a magnetic field that oscillates at very high frequency, the currents generated in the particle heat up the local region of DNA causing it to unwind (see image above) and become inactive. When the field is turned off DNA returns to its original shape and regains its function.

More info:
Hamad-Schifferli, K. et al.; Remote electronic control of DNA hybridization through inductive coupling to an attached metal nanocrystal antenna. Nature 415, 152-155 (2002).

The schematic of the process is from MIT website.

Working with Nature as a whole


Andy Goldsworthy is a British sculptor, photographer and environmentalist living in Scotland whose art is made of natural and found materials. His art is often temporary, made of fragile leaves, flowers, icicles, snow and everything else he finds on site of installation. He says: "I think it's incredibly brave to be working flowers and leaves and petals. But I have to: I can't edit the materials I work with. My remit is to work with nature as a whole."

More info about the artist is on wikipedia.org

Image of Andy's snow sculpture is from Art Forum Berlin.

11.06.2007

Materials from biomass



The full potential of biomass is not fully utilized even with already well established production of alternative fuels. Many products in biomass contain specific functionalities such as amino groups that are attractive in production of chemicals. Currently, most of the reagents that could be obtained from biomass are prepared by the conversion of crude oil products with the aid of co-reagents such as ammonia and complicated processing steps. For number of reasons, it is attractive to use biomass for the production of functional chemicals.

More info:
Scott, E. et al.; Biomass in the manufacture of industrial products—the use of proteins and amino acids. Appl Microbiol Biotechnol. 75: 751–762 (2007).

Lange J.P. et al.; Towards bio-based Nylon: conversion of gamma-valerolactone to methyl pentenoate under catalytic distillation conditions. Chem. Commun. 3488 - 3490, DOI: 10.1039/b705782b (2007).

10.31.2007

Snowflakes



Everything you always wanted to know about snowflakes is beautifully documented on snowcrystals.com. Kenneth G. Libbrecht, the author of the website included everything from science to art of these intricate, yet fragile natural microscopic structures.


Image from here.

Gel door to cell nucleus



The nuclear pore complex is an amazing piece of protein machinery residing at the interface between cell's nucleus and cytoplasm. It is open and inviting for solutes, water, ions and tiny metabolites, but larger molecules get in and out only with the proper passport. These heavy molecules have to recruit a receptor to pass through the narrow channel. Steffen Frey and his German colleagues have described a beautiful gel-like material that fills up these pores. Small molecules pass easily, but larger molecules have to bore a tunnel through this intelligent filter. They do it by temporarily damaging linkages between the molecules, thus destroying the network structure. After the molecule passes through, the passage cures and filter is impassable again.

More info:
Frey, S. et al.; FG-rich repeats of nuclear pore proteins form a three-dimensional meshwork with hydrogel-like properties Science 314, 815-817 (2006).

Golrich, D. and Kutay, U.; Transport between the cell nucleus and the cytoplasm. Ann Rev of Cell and Dev Biology 15, 607-660 (1999).

Image based on figures in Akey, C.W. & Radermacher, M.; Architecture of the Xenopus nuclear pore complex revealed by three- dimensional cryo-electron microscopy. Journal of Cell Biology 122, 1-19 (1993).

Perfectly transparent materials



Even Charles Darwin was amazed by its complexity and unusual material properties and debated whether the vertebrate eye was a result of natural selection. The reason for the almost perfect transparency has been discussed for decades. In 1962 Trokel proposed that proteins making up our eye lens were ordered in paracrystalline state over large distances. The interference of diffracted light would destroy all scattered light making it supertransparent. In 1983 Delaye and Tardieu concluded that paracrystalline order is not necessary to explain this remarkable property. In a simple experiment they have shown that the order has to be maintained only in short range with neighboring molecules.

The lens grows throughout life. Its cells lose their nuclei and other organelles that would otherwise scatter light. New layers of these cells keep growing over their predecessors, and the center is composed of original cells of embryonic origin. There is little or no protein turnover in the differentiated fiber cells. This means that the proteins of the lens can be extremely old and may be exposed to bright light for decades. The dominant proteins are crystallins that are thought to be responsible for the optical properties of this tissue.

The crystallins in the lens are closely related to molecules found in heat-shock proteins, calcium-binding proteins in bacteria, antigen in schistosome egg and other enzymes. Even though they have different origins, the expression of all crystallins is developmentally and spatially regulated in a manner that contributes to the subtle gradients of refractive index defining the exquisite optical properties of the tissue.

In addition, there is no blood circulation in these eye structures. Cursiefen et al. in 2006 have identified proteins that cause absence of any blood vessels in the clear structures of eye.

More info:

Delaye, M. & Tardieu, A.; Short-range order of crystalline proteins accounts for eye lens transparency. Nature 302, 415-417 (1983).

Cursiefen, C et al.; Nonvascular VEGF receptor 3 expression by corneal epithelium maintains avascularity and vision; PNAS 103, 11405-11410 (2006).

Wistow, G.J. & Piatigorsky, J.; Lens crystallins: The evolution and expression of proteins for a highly specialized tissue. Annual Review of Biochemistry 57, 479-504 (1988).

10.19.2007

Floral telegraph



Researcher Josef Stuefer at Radboud University, Nijmegen, Netherlands has analyzed clover plants and not only shown that these plants form underground networks of roots and stems, but more interestingly, they are capable of sending messages through these networks. Other plants such as strawberries also reproduce by runners and these stay intact even after the daughter plant matures. The researchers have shown that a plant in danger can immediately pass a signal through these runners, warn other plants. In turn these plants make themselves somehow less attractive and more resistant to the diseases or predators.

More info:

Stuefer, J.F. et al.; Clonal integration beyond resource sharing: implications for defence signalling and disease transmission in clonal plant networks. Evolutionary Ecology 18, 647-667 (2004).

Gomez, S. et al.; Cost and benefits of induced resistance in a clonal plant network. Oecologia 153, 921-930 (2007).

Image is from Radboud University.

10.04.2007

Wired or not?



In his recent news article in Nature, Philip Ball offers two conflicting opinions by researchers who study soil bacteria. There is a strong evidence for existence of nanowires produced by these microbes, but the function and purpose of these nanoscopic features has not been identified yet and remains the focus of a debate.

Read the whole article:

Ball P.; Bacteria May be wiring up the soil. Nature 449, 388 (2007)

Micromachine fabrication



Scientists at the Hokkaido University in Sapporo, Japan have fabricated microscopic tracks for Gluconacetobacter xylinus, bacteria that crawl on the surface and produce cellulose. "This fabrication technique is an example of how microorganisms can be utilized as micromachines for constructing new materials with micro-architecture, and will be applied to the creation of other patterned materials using microorganisms that secrete extracellular matrixes."

More information:

Uraki, Y. et al.; Honeycomb-like architecture produced by living bacteria, Gluconacetobacter xylinus. Carbohydrate Polymers 69, 1-6 (2007).

9.20.2007

Living and learning memory chip



Physicists Baruchi and Ben-Jacob at Tel Aviv University in Israel have demonstrated that neurons cultured outside the brain can be imprinted with multiple rudimentary memories that persist for days without interfering with or wiping out others. The image shows a micropipet used for local chemical stimulation of neurons grown on the recording electrodes. According to Ben-Jacob, their results will lead to the creation of a neuromemory chip that could be paired with computer hardware to perform such tasks as detecting dangerous toxins in the air, allowing the blind to see or helping someone who is paralyzed regain some if not all muscle use.

More reading:

Swaminathan N.; A Step Toward a Living, Learning Memory Chip. scientificamerican.com, June 2007

Baruchi, I. and Ben-Jacob, E.; Towards neuro-memory-chip: Imprinting multiple memories in cultured neural networks. Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 75 (5), art. no. 050901 (2007)