Scientists from Harvard University have created a tiny artificial stingray robot that can move through water just like the real thing, powered by living rat muscle cells.
The creation is called a biohybrid -- part robot, part biological tissue -- and was created by a team from Harvard University's Department of Bioengineering and Applied Sciences, led by bioengineer Kevin Kit Parker.
Parker dreams of one day creating a biohybrid artificial heart that can move and grow naturally, unlike the artificial heart pumps currently in use.
So after being inspired by the efficient movement of stingrays at the New England Aquarium, Parker set out to create a stingray robot.
Four years later, his creation is only about the size of a nickel, but its innovations are huge.
They robot’s stingray was created by sandwiching a stiff by flexible skeleton of gold between two layers of transparent elastic polymer.
Then, along the robotic ray, the team aligned 200,000 muscle cells from rat hearts in an S-shape, back-and-forth pattern.
All the muscles cells, called cardiomyocytes, had been genetically altered to respond to light.
When stimulated by light pulses, the cells contract and send a signal along to other cells down the line. Different frequencies of light pulses control the robot’s speed, while asymmetrical pulses can turn the robot to the left or right.
The result is that the robot’s “fins” move in an undulating motion, much like the movement of a real stingray, or like doing the wave in a stadium.
The robot responds to the light signals so well, the team reports in this week’s Science journal that it can be guided through obstacle courses.
Parker hopes his robot can serve as an example of how a biohybrid heart could one day be built to contract and relax to pump blood through the body.
The team still has a few hurdles to surmount before that could happen. For example, Parker’s “living robot” needs to be kept in a salt-sugar solution warmed to the internal temperature of a rat, to sustain the muscle cells.
“For me this was just a training exercise,” Parker told Science magazine. “I’m trying to get better and better at building muscular pumps.”
