In the series "A Modest Proposal," my colleagues and I will propose inventions and projects that I think are eminently doable and would love made real.

The very first post for this blog had to do with conjecture that it might one day be possible to manufacture brains, or people. This was no idle speculation, but a suggestion from tissue engineer Vladimir Mironov. The idea would be to use a 3-D printer, which deposits materials such as cells in solutions onto surfaces much as regular printers do with ink on paper.

The idea of copying a human brain is a formidable one, to say the least. However, one project Mironov did think was doable was 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 explained. "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."

Recently, scientists at the University of Illinois at Urbana-Champaign demonstrated their own bio-bot, made with rat heart cells that automatically contracted in unison.

These pulsations led to bio-bots that could inch their way across surfaces like caterpillars.

Earlier work developed an artificial jellyfish bio-bot:

This was made from rat heart cells as well:

In addition to bio-printing, I recently wrote about how 3-D printing is enabling the creation of a variety of robotic devices. Many of these were inspired by biology.

The scientists who developed the artificial walking bio-bot talked about how they would one day like to print neurons onto the muscles driving the bio-bots to give them a way to more intelligently respond to their environments. Given that 3-D printing can lay down circuits, maybe it'd be more feasible to print circuits onto bio-bots? Food for thought.

You can email me regarding A Modest Proposal at and follow the series on Twitter at #modestproposal.