Scientists are experimenting non-stop with additive manufacturing (AM). Moving into realms far beyond rapid prototyping, AM offers researchers the flexibility to build whatever tools or experimental objects are required. This does, of course, require some trial and error, but each successful step makes using AM technology that much more attractive.
Researchers at the University of Illinois at Urbana-Champaign are using 3D printing to create what they call “bio bots.” Generally, when people think of robots, they envision machines built from materials such as hard plastic or metals. Those kinds of materials are hardly ideal for certain applications, however, such as diving into the bloodstream of a patient.
“As engineers, we’ve always built things with hard materials, materials that are very predictable, said Rashid Bashir, an Abel Bliss Professor of Engineering. Yet there are a lot of applications where nature solves a problem in such an elegant way. Can we replicate some of that if we can understand how to put things together with cells?”
Bashir’s team used a HeCd laser and galvanometer scanning mirrors to build a stereolithography 3D printer. As one would expect with AM, each bot was built a layer at a time. The first layer to be completed consisted of soft cantilever hyrdrogel, followed by a more rigid hydrogel precursor solution. Next came the biological “motor” for the bots. From the published research paper:
Cardiomyocytes derived from neonatal rat hearts were extracted and seeded onto the cantilevers. The cardiomyocytes attached to the cantilevers, increased in size, and exhibited spontaneous contractile activity. Over several days, they produced a confluent culture and formed a cardiac cell sheet that contracted in synchrony.
The end result was a series of bio bots measuring between 5 to 10 mm. The slow beating of the bio motor allowed the bots to move forward with at a max speed of ~236 µm s−1. If you think of a slightly awkward inchworm, well, inching forward, you have about the right idea of how the bio bots move.
So, what are the potential applications for the bio bots?
“Our goal is to see if we can get this thing to move toward chemical gradients, so we could eventually design something that can look for a specific toxin and then try to neutralize it,” said Bashir. “Now you can think about a sensor that’s moving and constantly sampling and doing something useful, in medicine and the environment. The applications could be many, depending on what cell types we use and where we want to go with it.”
The Illini research paper titled, “Development of Miniaturized Walking Biological Machines” can be found at Scientific Reports.
Below you’ll find a short video about the bio bots.