The World's Smallest Thinker

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A microscopic version of Rodin's famed sculpture "The Thinker" is just about twice the size of a red blood cell at 20 millionths of a meter high. (Image credit: Dong-Yol Yang et al., Applied Physics Letters)

Using lasers, Korean researchers have crafted a microscopic version of Rodin's famed sculpture "The Thinker" just about twice the size of a red blood cell at 20 millionths of a meter high [image].

Muscles and even toes are visible in the tiny model.

For more than a decade, researchers worldwide have experimented with lasers to fabricate elaborate 3-D creations. They start with a resin that hardens when exposed to certain frequencies of light. Using overlapping beams of lasers, researchers can then solidify a sculpture with details measuring less than a wavelength of visible light in size.

While the skins of these sculptures are hard, their innards remain soft. This leaves them vulnerable to surface tension, the same force that causes water to bead up into droplets. The surface tension of the fluid in which the sculptures are immersed can cause them to deform.

These sculptures can by made stronger by increasing the power of the laser beams or leaving the beams on longer. This makes each spot on the surface of these sculptures extend deeper, yielding a thicker skin. Unfortunately, each spot now also takes up more surface area, sacrificing detail.

To solve this problem mechanical engineer Dong-Yol Yang at the Korea Advanced Institute of Science and Technology in Daejeon, South Korea, and his colleagues use multiple laser beams focused at and below each spot on the surface of thea sculpture [graphic]. The result is a thicker skin without each spot taking up more surface area.

With this new approach, the scientists scanned a replica of Rodin's popular masterpiece "The Thinker," originally sculpted in 1880, and created a version 93,000 times smaller than the roughly 6-foot-high original.

Yang and his colleagues reported their findings online Jan. 4 via the journal Applied Physics Letters.

Charles Q. Choi
Charles Q. Choi
Live Science Contributor
Charles Q. Choi is a contributing writer for Live Science and Space.com. He covers all things human origins and astronomy as well as physics, animals and general science topics. Charles has a Master of Arts degree from the University of Missouri-Columbia, School of Journalism and a Bachelor of Arts degree from the University of South Florida. Charles has visited every continent on Earth, drinking rancid yak butter tea in Lhasa, snorkeling with sea lions in the Galapagos and even climbing an iceberg in Antarctica.