3D printed bio-bots are crawling about the Heartland. Not very rapidly it is true, but at ¼mm
each second, just fast enough to be creepy. The body of cross-linked hydrogel
may seem harmless enough, but the power supplies were muscle cells from a rat’s
heart.
The work was done in the U of Illinois and the paper by Chan et al
was published in Nature’s Scientific Reports (1, 2). The bodies of the new breed
of bio-bots were printed out from an acrylate-modified polyethylene glycol, which
was cross-linked by UV light.
These body were printed on top of the “legs” of the bio-bots, which
were also of a cross-linked polyethylene glycol, but with a lower cross-linked
density so that their elasticity would be a good match for that of the heart-muscle
of the lab rats destined for immortality. Finally, a layer of rat heart-muscle
cells was added onto the underside of the legs.
With the beating of the
heart cells with a rhythm around one beat per second, their single legs twitched back and
forth kicking the bio-bots forward. In the future, control of the beating
heart-muscle can be driven by chemical gradients or light as well as simple
electrical impulses.
We can look forward to
bio-bots creeping around with a pacemaker fitted in the base on some mission of
mercy. It’s a pity that we can’t go straight to the heart of the matter and
train rats for the job.
- http://www.nature.com/srep/2012/121115/srep00857/full/srep00857.html
- http://www.bbc.co.uk/news/technology-20354026
