Nanotech News: Tiny Propellers for Drug Delivery

NanopropellersThe scientific and medical research communities have been looking to develop robots that measure in the nanometer range (that’s one-billionth of a meter) for quite some time. Being so small, they would be able to perform difficult tasks, such as targeted drug delivery to specific cells, or the elimination of harmful antigens, pathogens or viruses. However, the development of such machines raises numerous challenges.

For one, making them small enough to fit between cells remains tricky, and these tiny bots would also need a propulsion system that will allow them to navigate their way through the human body. But now, in a paper published in the June 2014 issue of ACS Nano, an Israeli and German team announced the creation of the smallest nanobot yet, a magnet-guided corkscrew which is propelled by a tiny helical propeller.

Nanopropellers1The team is comprised of researchers from the Technion-Israel Institute of Technology, the Max Planck Institute for Intelligent Systems, and the Institute for Physical Chemistry at the University of Stuttgart, Germany. Led by Dr. Peer Fischer at the Max Planck Institute, the research team created the tiny helical nanopropeller from a filament of silica and nickel that measures just 70 nanometers in diameter and 400 in length.

That’s more than 1,000 times smaller than the width of a human hair, or 100 times smaller than a single red blood cell, making the wee machine the tiniest nanopropeller humanity has ever created. Instead of carrying its own motor, the propeller is powered by an externally-applied weak rotating magnetic field which causes the prop to spin, driving it and its attached payload forward.

nanotech-2In order to test it, the scientist placed it in a hyaluronan gel, which is similar in consistency to bodily fluids. Like those fluids, the gel contains a mesh of entangled long polymer protein chains. In previous studies, larger micrometer-sized propellers got caught in these chains, slowing or completely halting their progress. The new nanoprop, however, was able to move relatively quickly by simply passing through the gaps in the mesh.

The study’s co-author, Associate Professor Alex Leshanksy of the Technion Faculty of Chemical Engineering, said that the nanobots:

actually display significantly enhanced propulsion velocities, exceeding the highest speeds measured in glycerin as compared with micro-propellers, which show very low or negligible propulsion.

The applications for this device certainly include targeted drug delivery, where the nanobots would be equipped with insulin, antibiotics, or even chemotherapy drugs which they could then deliver to specific cells in the body to speed up the delivery process and reduce side-effects. Scientists could also attach “active molecules” to the tips of the propellers, or use the propellers to deliver tiny doses of radiation.

nanobotsThe applications seem wide, varied, and exciting, from combating diabetes to fighting cancer and HIV with surgical precision. And developments like these, though they measure in the billionth of meters, they add up to a future where lives are healthier, longer and more prosperous.

Sources: engadget.com, gizmag.com, ats.org

The Future of Computing: Graphene Chips and Transistors

computer_chip4The basic law of computer evolution, known as Moore’s Law, teaches that within every two years, the number of transistors on a computer chip will double. What this means is that every couple of years, computer speeds will double, effectively making the previous technology obsolete. Recently, analysts have refined this period to about 18 months or less, as the rate of increase itself seems to be increasing.

This explosion in computing power is due to ongoing improvements in the field of miniaturization. As the component pieces get smaller and smaller, engineers are able to cram more and more of them onto chips of the same size. However, it does make one wonder just how far it will all go. Certainly there is a limit to how small things can get before they cease working.

GrapheneAccording to the International Technology Roadmap for Semiconductors (ITRS), a standard which has been established by the industry’s top experts, that limit will be reached in 2015. By then, engineers will have reached the threshold of 22 nanometers, the limit of thickness before the copper wiring that currently connect the billions of transistors in a modern CPU or GPU will be made unworkable due to resistance and other mechanical issues.

However, recent revelations about the material known as graphene show that it is not hampered by the same mechanical restrictions. As such, it could theoretically be scaled down to the point where it is just a few nanometers, allowing for the creation of computer chips that are orders of magnitude more dense and powerful, while consuming less energy.

IBM-Graphene-ICBack in 2011, IBM built what it called the first graphene integrated circuit, but in truth, only some of the transistors and inductors were made of graphene while other standard components (like copper wiring) was still employed. But now, a team at the University of California Santa Barbara (UCSB) have proposed the first all-graphene chip, where the transistors and interconnects are monolithically patterned on a single sheet of graphene.

In their research paper, “Proposal for all-graphene monolithic logic circuits,” the UCSB researchers say that:

[D]evices and interconnects can be built using the ‘same starting material’ — graphene… all-graphene circuits can surpass the static performances of the 22nm complementary metal-oxide-semiconductor devices.

graphene_transistormodelTo build an all-graphene IC (pictured here), the researchers propose using one of graphene’s interesting qualities, that depending on its thickness it behaves in different ways. Narrow ribbons of graphene are semiconducting, ideal for making transistors while wider ribbons are metallic, ideal for gates and interconnects.

For now, the UCSB team’s design is simply a computer model that should technically work, but which hasn’t been built yet. In theory, though, with the worldwide efforts to improve high-quality graphene production and patterning, it should only be a few years before an all-graphene integrated circuit is built. As for full-scale commercial production, that is likely to take a decade or so.

When that happens though, another explosive period of growth in computing speed, coupled with lower power consumption is to be expected. From there, subsequent leaps are likely to involve carbon nanotubes components, true quantum computing, and perhaps even biotechnological circuits. Oh the places it will all go!

Source: extremetech.com