By combining lab-grown muscle tissue with flexible mechanical joints, scientists have developed an artificial hand capable of gripping and making gestures. This breakthrough paves the way for a new era of robotics with diverse potential applications.

Figure 1. Breakthrough in Biohybrid Hands: Fusion of Muscle Tissue and Mechanics.

Although we've encountered numerous soft robots and innovative mechanical prosthetics at New Atlas, there haven't been many inventions that truly integrate human tissue with machines. This is likely due to the fact that biohybrid science is still in its early stages. While there has been an artificial fish powered by human heart cells and a robot that used a locust's ear to hear, the practical application of this technology remains limited. Figure 1 shows Breakthrough in Biohybrid Hands: Fusion of Muscle Tissue and Mechanics.

Researchers from the University of Tokyo and Waseda University in Japan have made a breakthrough showcasing the true potential of biohybrid technology.

To create their biohybrid hand, they first cultivated muscle fibers in the lab. Since the tissues alone lacked sufficient strength to function without tearing, the team bundled them into what they call multiple tissue actuators, or MuMuTAs. These actuators were then attached to a 3D-printed plastic hand with movable joints, measuring around 18 cm (7 in) in length.

Shoji Takeuchi, a co-author of the study published in Science Robotics, explained, "Our key achievement was developing the MuMuTAs. These are thin strands of muscle tissue grown in a culture medium and rolled into bundles, like sushi rolls, to form each tendon. Creating the MuMuTAs allowed us to overcome our main challenge, which was generating enough contractile force and length in the muscles to move the large structure of the hand."

Once the MuMuTAs were connected to the artificial hand, the researchers stimulated them with electrical currents. This enabled the hand to perform a scissor gesture, as well as grasp and manipulate a pipette's tip.

Most intriguing, the team observed that, similar to a human hand, the biohybrid model experienced "fatigue," with the muscle force decreasing over time with use.

"While not entirely surprising, it was interesting that the contractile force of the tissues decreased and showed signs of fatigue after 10 minutes of electrical stimulation, yet recovered within just one hour of rest," said Takeuchi. "Observing such a recovery response, similar to that of living tissues, in engineered muscle tissues was a remarkable and fascinating outcome."

Takeuchi and his team acknowledge that the hand is primarily a proof of concept rather than a fully functional device, and it still has a long way to go before its practical application. For instance, during the study, the entire hand was suspended in liquid to minimize friction and allow the joints to move more freely. The suspension also helped the hand return to a neutral position after being flexed by the lab-grown tendons. However, the team suggests that adding elastic materials or more MuMuTAs arranged in the opposite direction could address this issue.

Despite these challenges, the researchers believe that bundling tissue together represents a significant step forward in the scalability of biohybrids. Previously, such devices were limited to sizes of just a centimeter or so (about half an inch), so an 18 cm-long hand marks a major advancement.

"A major goal of biohybrid robotics is to mimic biological systems, which requires scaling up their size," Takeuchi explained. "The development of the MuMuTAs is an important milestone toward achieving this. The field of biohybrid robotics is still in its early stages, with many foundational challenges to overcome. Once these basic hurdles are addressed, this technology could be used in advanced prosthetics and serve as a tool for understanding how muscle tissues function in biological systems, as well as for testing surgical procedures or drugs targeting muscle tissues."

Source: NEW ATLAS

Cite this article:

Priyadharshini S (2025),” Breakthrough in Biohybrid Hand: Where Muscle Tissue Meets Mechanics" , AnaTechmaz, pp.127