Sometimes nature provides the best models for building efficient robots. It can also provide the best material. Billions of years of natural selection have built some pretty impressive machines, so you can’t really blame engineers for taking a little inspiration from the world around them. In particular, the field of soft robotics – with its flexible and compliant components – owes much to animal biology.
Although these systems have flexible shapes, many of their components remain rigid, like their more traditional counterparts. Researchers are working to provide flexible elements to create the locomotion of these soft robots. As MIT succinctly puts it, “our muscles are nature’s perfect actuators.”
However, the team goes beyond just imitating muscles. Researchers at the school are using living muscle tissue in tandem with synthetic robot parts for a classification of robots known as “biohybrids.”
MIT engineering professor Ritu Raman confirmed the process with TechCrunch, noting: “We build the muscle tissues from mouse cells, and then we place the muscle tissues on the skeleton of our robot. The muscles then function as actuators for the robot: each time the muscle contracts, the robot moves.
The muscle fibers are attached to a “spring-like” device called a “flexor,” which serves as a sort of skeletal structure for the system. Biological muscle tissue can be difficult to work with and generally unpredictable. Left in a petri dish, the tissue will expand and contract as hoped, but not in a controlled way.
To be deployed in robotic systems, they must be reliable, predictable and reproducible. In this case, this requires the use of structures that are flexible in one direction and resistant in the other. Raman’s team found a solution in Professor Martin Culpepper’s fabrication lab at MIT.
It was still necessary to adapt the flexions to the specifications of the robot to finally opt for structures at 1/100.th stiffness of muscle tissue. “When the muscle contracts, all the force is converted into movement in that direction,” notes Raman. That’s a huge magnification.
The muscle fiber/flexion system can be applied to different types of robots of different sizes, but Raman says the team is focused on creating extremely small robots that could one day work inside the body to perform mini procedures. -invasive.
techcrunch
