Originally Published September 2000
Small Things Considered
To cement their might and technological prowess in the eyes of the world, societies historically have built towering monuments. Pyramids, cathedrals, and skyscrapers may serve different functions, but their builders shared a common goal: to erect the tallest, most-imposing edifice known to man. Size still matters in the new century, but there's been a change in scale. Tomorrow's architectural marvels will be about the size of the period at the end of this sentence.
An article in the June 30 issue of Science magazine reports on the development of microrobots at Linköping University in Sweden. In "Microrobots for Micrometer-Size Objects in Aqueous Media," Edwin W. H. Jager and his fellow researchers describe the fabrication of individually controlled microactuators, micrometer-size manipulators, and microrobotic arms that can manipulate biological objects.
Composed of layers of conductive polymer and gold, the microrobots have flexible elbow and wrist joints and can incorporate hands made up of two to four fingers. An electrical charge applied through tiny wires makes the polymer shrink and swell, thus causing the joints to bend. Measuring 670 µm long and 170 or 240 µm wide, depending on the width of the wires, the microrobots can pick up, lift, move, and place micrometer-size objects within an area of about 250 x 100 µm.
Because they can function in salt solutions, blood plasma, urine, and cell culture media, Jager suggests that the devices may be suited for use as a tool in minimally invasive surgery. For example, a small robot placed on a catheter tip could increase the range of the surgeon, he writes. The micromachines could also have applications in multistation single-cell diagnostics, adds Jager, and could even be put to work building other microstructures.
Nanotechnology has the potential to achieve such phenomenal exploits that it's easy to get carried away on speculative flights of fancy. Along those lines, I found some interesting thoughts at the site for NanoTechnology magazine, http://www.nanozine.com. Under the title "Super Medicine," an anonymous author envisions an army of medical "nanites" patrolling the body. Armed with complete knowledge of a person's DNA, the nanites would act like an intracorporeal missile defense system, neutralizing foreign invaders before they can launch an attack. These cell sentinels, the author writes, could form an artificial immune system to protect its host from everything from the common cold to AIDS. But why stop there? Buoyed by the endless possibilities, the author predicts that nanites could perform the work of a plastic surgeon from within the body and even perform sex-change operations. "Men could bear children," the writer breathlessly proclaims.
Time for a reality check? Then turn to this month's industry news, where we take a look inside a camera in a pill. Incorporating a sensor that transmits color images as it passes through the stomach and small bowel, the disposable capsule is described as a painless alternative to invasive gastrointestinal endoscopy. The device is currently undergoing clinical trials, and Given Imaging Ltd. hopes to be able to market the pill by the end of this year.
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