In PopSci’s recurring Shrinkage feature, we tip our hats to the scientists whose work is devoted to the noble cause of making our world a little tinier, one gadget at a time. Consider the “memory stamp” pictured above-about the size of your pencil point, it can store the same amount of data that formerly filled three comparatively massive 3.5-inch diskettes (remember those?). For a look at more of the most amazing developments in the quest to make extremely small things, launch the photo gallery here.

Perfect Plumbing

Scientists invent super-smooth, super-small pipes that could ferry medicine into the body Scientists at the University of Kentucky have built tiny pipes that move water 10,000 times as fast as the conventional laws of fluid flow allow, mimicking for the first time the seamless way fluids progress through our cells. They´ve also found a way to control which molecules can pass through the pipes, a discovery that could yield safer, more efficient skin patches to deliver medicine into the body. The pipes are made of carbon nanotubes, thin sheets of graphite rolled into cylinders just seven billionths of a meter in diameter. The scientists poured a polymer between them to create a fine membrane that can embed 65 billion pipes per square inch. Lead researcher Bruce Hinds attributes the tremendous speed of the water flow (3.3 feet a second) to the nearly friction-free carbon nanotube walls. To keep out unwanted molecules, Hinds placed chemical receptors at the entrances to each tube, so that only those proteins that match the receptors are allowed passage.-Gregory Mone

Follow the Money

New ultrathin radio ID tags embedded in money can thwart counterfeiters For years, radio-frequency identification, or RFID, tags have been used to track everything from highway tolls to pets, but only Hitachi´s newest tag is skinny enough to fit inside a dollar bill. Just 0.15 millimeter square and 7.5 microns thick, it´s a mere 1/15 the size of the next smallest RFID chip. And it can do everything its predecessors can. Hitachi´s tags store up to 128 bits of data-including prices, serial numbers and places of origin-that radio scanners can read from more than 10 feet away. RFID chips typically use thick metal guard rings to insulate their circuitry. The insulation limits electrical interference but makes the tags too bulky for thin products such as paper. Hitachi´s weight-loss solution is to remove the rings and separate the circuits into individual wells coated with a thin insulating layer of silicon dioxide. So far, the new insulation trick has worked perfectly. An earlier version of the chip successfully debuted in tickets for the 2005 World Exposition in Aichi, Japan, as a way to stop counterfeiters, and a new, even slimmer version could appear in European and Japanese currency within the next few years. When that happens, banks and businesses can simply scan the tagged bills to confirm their authenticity or trace their origins.-Elizabeth Svoboda

The World´s Smallest Projector

New research turns your PDA into a movie theater The Fraunhofer institute helped make our music collections pocket-size by inventing MP3 compression, and now it´s made video equally mobile. Researchers at the German think tank have crammed a video projector into a box about the size of a sugar cube. This feat of miniaturization could be the first step toward portable gadgets that project big-screen images wherever you go. In traditional digital projectors-the kind you might find in a conference room or home theater-microscopic mirrors tip back and forth to switch individual pixels on or off. A typical projector requires nearly 800,000 mirrors and a single lamp large enough to illuminate the entire array, all of which add bulk to its frame. The researchers´ mass-shedding trick was to use a single mirror just two hundredths of an inch in diameter. Instead of remaining stationary, the mirror does the job of many by rapidly tilting in two directions, projecting individual pixels across the screen in an oscillating wave that converges to complete a 20-inch image. Microvision, an imaging company in Redmond, Washington, has incorporated the technology in a tiny prototype projector that debuted in January.-Eric Mika

Atomic Pencil Sharpener

A mishap in the lab creates the world´s sharpest point Sometimes an accident isn´t such a bad thing. When physicist Bob Wolkow and his colleagues at the National Institute for Nanotechnology in Canada were trying to sharpen the tip of an electron microscope to enhance its resolution, they failed to notice a small but significant leak in its vacuum chamber. The hidden leak had allowed nitrogen to creep inside the machine and scrape away atoms on the dull tip. The inadvertent result? The world´s finest pinpoint. âa‚¬It was kind of magical to see it happen,âa‚¬ Wolkow says. The atom-wide tip, which is five millionths the width of the head of a pin, could help scientists better visualize exceptionally small objects such as cells and phenomena currently too small to see with even today´s best scopes. Electron microscopes create highly magnified 3-D images by shooting electrons from an ultrafine tip. The finer the tip, the sharper the image. Scientists now rely on several sharpening techniques, one of which involves heating the tip, yet none of them has proven nearly as effective as Wolkow´s âa‚¬magicâa‚¬ nitrogen. The gas, Wolkow has discovered, binds to tungsten atoms on the perimeter of the tip. When zapped with an electric field, the bound clumps fall away like the wood-graphite shavings of a freshly sharpened pencil. Using this technique, Wolkow was able to hone the tungsten to a single atom and increase the resolution of his scope by an impressive 20-fold.-Gregory Mone

Powered by Germs

The trick to making paper-thin batteries? Viruses, lots of´ ´em Bid farewell to that brick on the back of your laptop. Massachusetts Institute of Technology researchers are developing a new breed of lithium-ion battery that´s razor-thin, transparent and more potent than current power cells. âa‚¬It looks like a piece of tape,âa‚¬ says Angela Belcher, the MIT materials scientist leading the effort. A light, see-through battery could open the door to less cumbersome computers, MP3 players and other gadgets. âa‚¬You could laminate on the battery just like you would a picture,âa‚¬ says Belcher, who made this magazine´s Brilliant 10 list in 2002. The secret to its slimness-weird alert-is a virus called M13. Most batteries stores energy in electrodes made of bulky carbon or metal. To cut weight and increase power, Belcher genetically engineered the harmless viruses to attract metal ions and then bathed them in a solution of cobalt oxide and gold, metals known for their superior energy-storage properties. Coating the viruses onto a charged polymer film created an electrode 40 times as thin as a human hair. Tests conducted earlier this year showed that it stored three times the energy of a conventional electrode. Expect the technology to go commercial within five years. -Michael Stroh

When Photos Talk

A new âa‚¬memory stampâa‚¬ turns physical objects like postcards and photos into hyperlinks Vacation snapshots are nice, but wouldn´t they be nicer if you could swipe your cellphone over them to retrieve video, sound files and captions? That´s the idea behind the Memory Spot, an adhesive chip in development at Hewlett-Packard´s Bristol, England, facility. The stamp-like memory device comes in two sizes, 1.4 or 2 millimeters square. Affixed to a photo or document, it can store and transfer up to four megabytes of data, enough for a short video or a couple songs. Howard Taub, associate director of HP Labs, likens the Memory Spot to radio-frequency identification (RFID) tags but notes some key differences. Both use radio waves to transfer data, but the Memory Spot works at a higher frequency. As a result, the antenna embedded in the chip-and the chip itself-can be thinner. The tradeoff is transmission distance: Whereas RFID can work from across a room, the Memory Spot requires nearly direct contact with a reader to transfer data. Ideally, the reader would be built into your phone or some other handheld device. Wave it over the Memory Spot, and in less than a second you´d have your file. Aside from photos, Taub says, the stamps could be used to store medical records on patient wristbands or to authenticate prescription-pill bottles. Expect it on store shelves in the next two years.-Gregory Mone

The Fine Print

Xerox unveils a new weapon against counterfeiters: teeny text Prepare to squint. Researchers at Xerox have created letters that stand only one hundredth of an inch tall. Printed inconspicuously on checks, birth certificates, school transcripts and other papers, they could distinguish authentic documents from fakes. Microprint itself isn´t new. Look at a credit card or $20 bill under a magnifying glass, and you´ll see that some of the dark lines and borders are actually strings of letters and numbers. But until recently, it was impossible to personalize these characters. Now, with the special Xerox font, anything can be custom-printed in miniature. For instance, in less than a minute, an employer could turn out 100 payroll checks with 100 unique names on each of them; custom-forging each check would be virtually impossible. As for verification, bankers could simply authenticate the checks by examining the microprint to make sure it matches the payee´s name. To create the font, Xerox researcher Reiner Eschbach and his colleagues wrote new software (for room-size commercial printers) that emphasizes ultraprecise alignment of the ink dots within each letter. The no-frills characters are readable even when miniaturized, unlike with more beautifully sculpted fonts. Most people won´t notice the microscopic writing on their documents. But, Eschbach says, âa‚¬the counterfeiter will know it´s there.âa‚¬-Dawn Stover