Stingray Soft Robot Uses Heart Cells for Movement

The year 2018 is off to a good start in terms of bio-inspired robotics, if my article assignment list is anything to go by. This is my third bio-inspired robotic article this week, and there is no sign that this trend is going to slow down anytime soon.

Artist's impression of robotic stingray. (Image courtesy of UCLA.)

Whereas the previous articles focused on individual bio-inspired components such as soft actuators and insect-like brains, in this article a new robot developed by researchers at UCLA steps things up a gear and combines several bio-inspired systems into one batoid-shaped package.

The UCLA soft robot, which measures just 10 mm in length and is stingray shaped, is composed of four different layers.

Those four layers consist of tissue that is made of live heart cells, two distinct types of specialized biomaterials for structural support, and flexible electrodes.

Stingrays, and other batoids, provide researchers with a good starting point because their body kinematics are relatively easy to model. Combine the body kinematics with the fact that batoids rely on hydrodynamic lift and drag to move through the water, and you have a platform that is fairly easy to simulate numerically, as well as fairly easy to construct.

Stingray wings just kinda flap up and down, and change angle a little bit. Something that is easy to model, but very effective. Stingrays have incredibly good maneuverability underwater—a testament to nature’s efficient design. And that is the first aspect of bioinspiration here.

The second part is the aforementioned multilayered skin. When the layer of electrodes is energized, heart cells contract, causing the robot to flap its wings, much like the muscles of a biological creature.

“The development of such bio-inspired systems could enable future robotics that contain both biological tissues and electronic systems,” said Ali Khademhosseini, UCLA bioengineering professor and leader of the project. “This advancement could be used for medical therapies such as personalized tissue patches to strengthen cardiac muscle tissue for heart attack patients.”

The research was supported by the Defense Threat Reduction Agency. Additional funding support came from the National Institutes of Health, the Presidential Early Career Award for Scientists and Engineers, and the Air Force Office of Sponsored Research.

The study has been published in the Advanced Materials journal, and can be seen at this link.