If printers have the power to manufacture organs, why not brains? Or people?

In "Too Hard for Science?" I interview scientists about ideas they would love to explore that they don't think could be investigated. For instance, they might involve machines beyond the realm of possibility, such as particle accelerators as big as the sun, or they might be completely unethical, such as lethal experiments involving people. This feature aims to look at the seemingly impossible dreams, the most intractable problems in science. However, the question mark at the end of "Too Hard For Science?" suggests that nothing might be impossible.

The scientist: Vladimir Mironov, director of the Advanced Tissue Biofabrication Center at the Medical University of South Carolina. An official statement from the Medical University of South Carolina noted that Mironov will be at Harvard beginning in the summer.

The idea: The inkjet printer technology typically seen in offices is now finding use in research aimed at manufacturing complex tissues and living organs. These "bio-printers" use suspensions of cells as their ink, printing them in layers to build three-dimensional structures following computer models from scientists.

"Bio-printing researchers are exploring liver, kidney, muscle, bone, and skin," Mironov says. "If we can print human organs, then by logical extension we can eventually print the whole human body, including the brain."

When it comes to humanity reaching other stars, instead of exposing astronauts to the dangers of interstellar travel, Mironov adds that spaceships could print out explorers at their destinations. A potential consequence of this concept of printing humans is the elimination of sex, birth and childhood, "the start of asexual human evolution," Mironov says.

The problem: Copying a human brain is, to say the least, a formidable task. The human brain has about 100 billion neurons with roughly 100 trillion connections wiring these cells together. "To copy a brain, our blueprint would need to know the specific location of every cell in the X, Y and Z axes and force them to grow the right connections with each other — that's a huge amount of information to deal with," Mironov says. "It would then be a real question of whether the brain would actually be functional, and how information would be loaded into this brain — all the memories a person accumulated in life."

The solution? "You must start very simple," Mironov says. He envisions beginning with circuits of three neurons and then increasing in complexity.

One project Mironov does think is doable is creating simple "bio-robots" using bio-printing — for instance, fish-shaped bundles of eye, nerve and muscle cells. "You can shine a light on the eye cells, which send a signal over the nerve cells to the muscle, so you can make it swim left or right," he explains. "I do not see any technical problems with the idea, but of course, people look at me like I am crazy when I suggest this."


If you have a scientist you would like to recommend I question, or you are a scientist with an idea you think might be too hard for science, email me at toohardforscience@gmail.com.

Follow Too Hard for Science? on Twitter by keeping track of the #2hard4sci hashtag.

About the Author: Charles Q. Choi is a frequent contributor to Scientific American. His work has also appeared in The New York Times, Science, Nature, Wired, and LiveScience, among others. In his spare time he has traveled to all seven continents. Follow him on Twitter @cqchoi.

The views expressed are those of the author and are not necessarily those of Scientific American.