Let's Get Small

"I'm on drugs. You know what I'm talking about ... I like to get small ... It's very dangerous for kids, because they get reeeally small ... I know I shouldn't get small when I'm driving, but I was drivin' around the other day and a cop pulls me over ... says, 'Hey, are you small?' I say, 'No, I'm tall, man, I'm tall.' He says, 'I'm gonna have to measure you.' They give you a little test with a balloon. If you can get inside it, they know you're small ... and they can't put you in a regular cell either, 'cause you walk right out."
-Steve Martin

Speaking of getting really small, collaborating teams of British and Russian scientists have developed a tape that could allow people to climb walls à la Spiderman with two palmfuls of the material that mimics the microscopic surface of gecko feet.

The soles of the gecko's feet are coated with millions of microscopic hairs. Each creates tiny forces of molecular attraction when in contact with a solid surface.

When all the hairs of its feet make contact, the combined adhesive force is stronger than many man-made glues, with the added benefit that its feet can be peeled away from the surface at any time to allow it to move one leg at a time. Professor Andre Geim, director of Manchester University's Centre for Mesoscience and Nanotechnology, used the principle to make reusable adhesive tape in collaboration with the Institute for Microelectronics Technology in Chemogolovka, Russia.

A 2mm-square segment of the tape was strong enough in one test to support a Spiderman toy - 15cm high and weighing 40g - by one hand from a glass ceiling. This means that covering the two palms of a man with the tape would enable his full weight to be supported, the scientists report in the journal Nature Materials.

Not small enough for you? Okay, how about flourescent lights 1000 times smaller than a red blood cell?

_{Credit: Bioimaging Resource/Cornell University}

Tiny blood vessels, viewed beneath a mouse's skin with a newly developed application of multiphoton microscopy, appear so bright and vivid in high-resolution images that researchers can see the vessel walls ripple with each heartbeat -- 640 times a minute. The capillaries are illuminated in unprecedented detail using fluorescence imaging labels, which are molecule-size nanocrystals called quantum dots circulating through the bloodstream. Quantum dots are microscopic metal or semiconductor boxes (in this case cadmium selenide-zinc sulfide) that hold a certain number of electrons and, thus, have a wide number of potential applications in electronics and photonics.

[...]

Webb explains that the laser scanning microscope used in multiphoton microscopy is particularly adept at producing high-resolution, three-dimensional images inside living tissue because it combines the energies of two photons, striking a molecule at the same time, with an additive effect. Under the conditions used, this only occurs at the focus of the laser, so only at that point is the molecule excited to a state that results in fluorescence emission. This excitation is the same as if it arose from the absorption of a single photon of higher energy, but it is three-dimensionally localized since it is only occurring at the beam focus. The scanning microscope moves the laser beam across the area being imaged at a precise depth. When repeated scans at different planes of focus are "stacked," the result is a brightly lit and vividly detailed three-dimensional image -- and video that takes a viewer inside a living organism.

What? That's still not small enough for you? Okay, but you're begging for an intervention. For now, I will go no smaller than this: a free-running perpetual motion motor made out of DNA. You can follow the link for the details, but the grossly oversimplified version is that researchers at Oxford and Lucent Technologies figured out a way to keep a small strand of DNA zipping and unzipping without having to feed it new strands. The excerpted implications:

The free-running DNA motor could eventually power microscopic machines capable of constructing and transporting chemicals and materials molecule by molecule. [...] "These [researchers] have put together a system that will, in principle, allow for a free-running machine." Such a machine could provide power for devices like nanorobots and nanomechanical computers, Seeman said. [...] The DNA motor could eventually power nanomachines for use in medicine, chemistry and materials science. [...] Eventually it may be possible to coax DNA to assemble into much more complicated structures, including molecular-scale electronic circuits.

Now that's small. Hey, quit nano-bogartin' the microjuana!