Organic Photovoltaic (OPVs) solar cells can achieve moderate power conversion efficiencies at low cost.

Arrays of atomic force probe tips are promising nanotech approaches to denser, faster, cheaper memories (see this post from nine months ago). James Tyrrell of nanotechweb.org (requires free registration) explores the latest progress from the IBM “millipede project” and looks at what yet needs to be done. The researchers have completed a fully functional prototypes system and demonstrated. They have further demonstrated accurate control of tip position at a scanning speed three to four orders of magnitude faster than a typical scanning probe microscope, and the ability to write more than 10⁸ indents at a density of 1 Tb per square inch with a single tip. From “Nanoindenter passes memory test“

Scanning probe-based data storage is back in the news as IBM researchers turn their attention to the thermo-mechanical indentation of polymer media at high patterning densities and fast transfer rates.

Results published in the journal Nanotechnology [abstract] suggest that there could be more mileage in polymer systems than experts first thought and nanotechweb.org interviews Urs Dürig of IBM’s Zurich Research Laboratory, Switzerland, to find out more.

What are the attractions of polymer probe technology compared with other data storage schemes?

Polymer probe technology offers the potential of extremely high storage density, up to 4 Tb/inch2. The basic principle of hot-embossing the information in the form of indents is conceptually simple and lends itself well to a highly parallel MEMS implementation. In this way, we address several critical issues. The data rate can be boosted by two to three orders of magnitude by operating a corresponding number of indenters in parallel. Small size also means low power consumption, which is critical in particular for portable applications. Small size also means robustness of the device against shock and vibration. Finally, small size also means fast positioning, which translates to worst case seek/access times in the order 1 ms in comparison with 10 ms for hard disk drives.

The researchers note that even with this impressive progress, a “millipede” type memory might not be competitive with flash memory. Regardless, the techniques for rapid and precise control of arrays of AFM tips might be of use to proposals for mechanosynthesis with AFM (see this post from two weeks ago and this one from three weeks ago).
—Jim

Nanotechnology advancements have affected almost every area of modern science, from pharmaceuticals to ceramics. Today, the development of nanotechnology applications in the field of agriculture is revolutionizing the farming industry. With large-scale investments from global food corporations, support from the academic community, and funding from many governments around the world, the opportunities for nanoparticles remain limitless in the agrichemical industry. Nano World News spoke with John Hill, Process and Applications Advisor for NETZSCH Fine Particle Technology in Exton, Pa., about the manufacturing and use of nanoparticles in agriculture.

Midatech, a company that focuses on the design, synthesis, and manufacture of biocompatible nanoparticles, recently announced the formation of a Basel-based Swiss drug development subsidiary, PharMida AG. The subsidiary follows an important investment by a group of Switzerland-based investors into Midatech Ltd. The mission of PharMida is to develop a strong portfolio of clinically validated gold nanoparticle-drug combinations. PharMida will have the responsibility to project manage in-house drug development, commercial partnerships, and out-licensing opportunities in order to leverage the collection of the already existing Midatech Ltd product lines in Life Sciences.

Canada

The inaugural Summit on the Global Agenda was held in Dubai in early November. The Summit invited 700 global thought leaders to discuss more than 30 leading Global Challenges of our Time, including nanotechnology, climate change, alternative energies, and corporate governance. The Summit noted that

The Nanotechnology Exhibit will be on display at the Colonie Center Mall through March, 2009. The exhibit is a showcase of nano-enabled consumer products (including the Xbox, the iPod Touch, and clothing) that sit next to the advanced technologies being developed at the College of Nanoscale Science and Engineering (CNSE) at the University of Albany, such as computer chips and solar cells. The Nano Exhibit is one of several activities being carried out by the CNSE as part of their NANOvember educational outreach initiative.

Nanotubes are of much interest for more than 15 years for applications in molecular electronics, transparent electrodes or functional composites. While working on the spectroscopy with individual carbon nanotubes we realized that nanotubes can be used to learn about optics at scales below the diffraction limit.

The need to regulate and control light power is relevant not only for sophisticated communication systems but also to everyday optical equipment such as cameras or car rear-view mirror and require an active electronic feedback control.

It has not been tested experimentally yet, but if a proposal to use graphene as a nanotech method to sequence DNA very rapidly and inexpensively pans out, the “wonder material” of nanotechnology could find yet another use. From nanotechweb.org, written by James Dacey (requires free registration) “Graphene could accelerate genomics“:

The “wonder material” graphene could soon be used to analyse DNA at a record-breaking pace. That’s the claim of a physicist in the US who has proposed a new way of reading the sequence of chemical bases in a DNA strand by sending the molecule through a tiny slit in a graphene sheet.

While the technique has yet to be verified experimentally, if successful it could be eligible for the $10 million X Prize for Genomics, which has set the challenge of developing a new rapid and low-cost sequencing technology.

…Henk Postma at California State University Northridge has proposed a way of sequencing an entire DNA strand without the need for blasting or computer processing (arXiv:0810.3035).

The technique involves cutting a very narrow slit or “nanogap” along the length of a piece of graphene — an extremely strong sheet of carbon just one atom thick. A voltage is applied perpendicular to the graphene’s surface, which causes the DNA strand to pass slowly through the slit one base at a time.

A second voltage is applied across slit and electrons are able to “tunnel” across the nanogap via the base that happens to be passing through the slit. There are four different types of base in a DNA molecule, and each should support a different tunnelling current — allowing the base type to be identified.

While the idea of sequencing DNA by sending it through a tiny gap is not new, previous schemes had relied on using separate materials for the membrane and electrodes — and aligning the two materials has proved to be a considerable challenge. Postma’s design gets around this problem by having the graphene function as both membrane and electrode.

—Jim