From this headline you probably have a lot of questions, so let us explain. This seemingly crazy science experiment was carried out by a collaboration between Harvard University and Emory University, with the end goal of growing an artificial heart that pumps on its own.

“Our ultimate goal is to build an artificial heart to replace a malformed heart in a child,” said Kit Parker, senior author of the paper. “Here, we are drawing design inspiration from the biophysics of the heart,” which is pretty hard to do. So instead of the team just using a diagram of a fish as a blueprint they are using a live swimming fish, where the levels of success of the experiment can be more accurately concluded.

The study, published in Science, explains that the mechanical device was designed in the shape of a zebrafish. This fish is a useful subject in biology, used to study many processes such as revealing how our brain stores our memories.

Two layers of cardiac stem cells were coated around the fin tail of the biodevice. When these contracted, the hybrid was propelled forward. The team also fitted a pacemaker to the muscle tissue, allowing for the generation of continuous and coordinated fin motions.

“By leveraging cardiac mechano-electrical signaling between two layers of muscle, we recreated the cycle where each contraction results automatically as a response to the stretching on the opposite side,” stated Keel Yong Lee, co-first author of the study. “The results highlight the role of feedback mechanisms in muscular pumps such as the heart.”

The team hopes to build an even more complex hybrid biodevice from human heart cells, expanding on their genius design. Eventually leading to the technology being used to save lives.

Source study: Science – An autonomously swimming biohybrid fish designed with human cardiac biophysics