3-D printer helps create a 'biobot'

These bots were made for walking — out of rat heart cells and hydrogel.

Scientists have paired these unlikely ingredients to create simple biological machines that look something like a front-loaded inchworm and can step their way through fluid at speeds up to 236 micrometers per second.

Bioengineers working at the boundary between organics and mechanics dream of harnessing the power of biology's nuts and bolts. Some have built tweezers out of DNA; others have made sensors by sticking bacteria on a chip. It's no easy task — plastic and metal are far more predictable materials to work with.

But in work published recently in Scientific Reports, a team of bioengineers described how they came up with a way to manufacture biobots quickly and efficiently with a three-dimensional printer.

The printer builds preprogrammed shapes layer by ultrathin layer, until it has constructed a soft "body" out of hydrogel, a class of polymers that includes the stuff contact lenses are made from, said senior author Rashid Bashir, a bioengineer at the University of Illinois at Urbana-Champaign.