Now, you can build your own 3D printed bio-bots

You could now 3D print your own tiny walking "bio-bots" powered by living muscle cells and controlled with electrical and light pulses, thanks to a new gen-next robot 'recipe' developed by scientists, including one of Indian origin.
This can result in exciting possibilities where these "systems could one day demonstrate complex behaviours including self-assembly, self-organisation, self-healing, and adaptation of composition and functionality to best suit their environment," researchers said.
"The protocol teaches every step of building a bio-bot, from 3D printing the skeleton to tissue engineering the skeletal muscle actuator, including manufacturers and part numbers for every single thing we use in the lab," said Ritu Raman, a postdoctoral fellow at the University of Illinois at Urbana-Champaign in the US.

"This protocol is essentially intended to be a one-stop reference for any scientist around the world who wants to replicate the results, and give them a framework for building their own bio-bots for a variety of applications," Raman said.
The team has been a pioneer in designing and building bio-bots, less than a centimetre in size, made of flexible 3D printed hydrogels and living cells.
In 2012, the group demonstrated bio-bots that could "walk" on their own, powered by beating heart cells from rats. However, heart cells constantly contract, denying researchers control over the bot's motion.

"The purpose of the paper was to provide the detailed recipes and protocols so that others can easily duplicate the work and help to further permeate the idea of 'building with biology' - so that other researchers and educators can have the tools and the knowledge to build these bio-hybrid systems and attempt to address challenges in health, medicine, and environment that we face as a society," said Rashid Bashir, head of the Department of Bioengineering at Illinois.

"The 3D printing revolution has given us the tools required to 'build with biology' in this way," Raman said.
"We re-designed the 3D-printed injection mold to produce skeletal muscle 'rings' that could be manually transferred to any of a wide variety of bio-bot skeletons," she said.
These rings were shown to produce passive and active tension forces similar to those generated by muscle strips.
"We worked with collaborators at Massachusetts Institute of Technology (MIT) to genetically engineer a light-responsive skeletal muscle cell line that could be stimulated to contract by pulses of 470-nm blue light," Raman added.
"The resultant optogenetic muscle rings were coupled to multi-legged bio-bot skeletons with symmetric geometric designs," she said.

"Localised stimulation of contraction, rendered possible by the greater spatiotemporal control of light stimuli over electrical stimuli, was used to drive directional locomotion and 2D rotational steering," said Raman.
The research appears in the journal Nature Protocols.