Why have scientists created this half-machine, half-flesh robo-stingray?

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A team of marvelous weirdos at Harvard have created what they are calling a ‘synthetic beast.’ It graces the cover of this month’s issue of Sciencewhich you are free to look at if you want it to haunt your mind for years and years to come.

It's a half-machine, half-flesh swimming robot made of a rubber body which gets its power from cells harvested from rat hearts; a gold skeleton; and nightmares. The purpose of the cyborg stingray is not to terrify young children at the beach but to help researchers better understand the human heart and heart disease by reverse engineering muscular pumps seen in nature. Studying living creatures can be challenging, so researchers have started to instead design robots they can experiment with.

The creature is guided by light, something which was achieved by genetically modifying rat heart cells to respond to light cues. They spasm in response, propelling the tiny, zombie Frankenstein through water. Luckily it is barely 10 mm in diameter.


The hybrid creature is not quite alive and not entirely synthetic either, which is a great step forward for unclassifiable monstrosities. Like all things too beautiful for this world, their lives are short—lasting only six days before they are no longer sentient. And they were the lucky ones, many prototypes along the way were lost and 'dysfunctional'; "Oh, Lord…scores," as one of their creators put it when estimating how many were sacrificed for science.


Who would create such a thing and why? I chatted over email with an engineer on the project, Kit Parker, who lays the blame for this abomination squarely at the feet of his perfectly innocent young daughter.

Elmo: Yes, hello! Why on Earth did you do this?

Kit: The Eureka moment for the project came when my daughter Caroline and I were at the New England Aquarium. She was trying to pet a stingray and she put her hand in the water and the stingray quickly moved away from her hand in a very elegant way. [The idea] struck me like a thunderbolt. I could build that system. The musculature would look very much like [the human heart].


I see, a very fruitful trip to the aquarium! Were there other inspirations? 

When my daughter was little I used to point a laser pointer at the ground and she would try to stomp on it. We would go for a walk down the street and I could lead her along the sidewalk safely but just pointing a laser pointer at the ground. It occurred to me that we could use optogenetics to mimic this with the tissue engineered stingray. So that's what we did.


[Optogenetics is a technique employed to genetically manipulate certain cell types to be responsive to stimulus from light sources, which has been tested extensively on mice. See the effect on the ray in the video below.]

Are there practical applications for this kind of work? What would the real-world use for a creature like this be?


To advance our studies of the human heart we have started looking at marine life forms and how their muscular pump works. The idea is to get a better insight into the human heart and heart disease by reverse engineering other forms of muscular pumps that we see in nature.

So then what is the advantage of creating synthetic hybrids over studying already existing animals?


Living muscle cells are much more energy efficient than synthetic replicas and can be programmed to do cool things, but the disadvantage is that cells as a building material have a vote in whether or not I am going to have a good day in the lab. They like to be wet, they are both robust and vulnerable, and they die. They are unpredictable. So [we turn to] robotics in order to do this research.

Are there plans to make more of these? (Let's hope!)

For us, it's mission accomplished. The ray is done and published, and the invention's covered by IP. The lessons learned are being applied to the study of heart disease so after this month we are walking away from it and moving on to the next project.


Well, congratulations and that does not sound at all ominous. Did you have a name for the creature while you were working on it? A nickname? 

It's a biohybrid soft robot so… I call it 'synthetic beast'. I am not sure my lab mates call it that, or if they call it anything that is suitable for family reading!


I understand.

It was a tough project.

Elmo is a writer with Real Future.