Inspired by the swimming mechanism of manta rays, a research team from the Shenyang Institute of Automation (SIA) of the Chinese Academy of Sciences (CAS), has developed a wireless near infrared light-controlled biosyncretic manta ray robot powered by isolated bullfrog skeletal muscle. The work was published in the international journal Advanced Functional Materials on August 13.

Biosyncretic robotics, which integrate living biological materials with non-living electromechanical systems at the molecular, cellular, and tissue levels represent a rapidly advancing frontier. Such systems offer unique advantages including high energy efficiency, self-growth, self-repair, and biocompatibility. However, existing skeletal muscle driven biosyncretic robots have long been constrained by low actuation force, poor maneuverability, and tethered control that limits real-world operational scenarios.

Model of the biosyncretic manta ray （Image by SIA）

Biomimetic mechanism of the biosyncretic manta ray（Image by SIA）

Rather than relying on engineered, lab‑reconstructed muscle tissues widely adopted across the field, the team innovatively employed native isolated skeletal muscle—specifically the Rana catesbeiana gracilis muscle—as the biological actuator. This natural tissue features highly ordered fiber architecture and superior contractile performance compared to lab reconstructed muscles. By optimizing electrical stimulation parameters (1 Hz, 5 V, 10 ms), the isolated muscle stably produced a contractile force of 6.5 N, with a peak output of 9.4 N under extreme conditions. In vitro culture tests confirmed that the muscle maintained electro contractile responsiveness for up to 11 days, and reliably powered the robot for 7 days of continuous operation.

For untethered actuation, the team constructed an integrated driving architecture combining near infrared (NIR) laser irradiation, photovoltaic conversion, and neural electrical stimulation. Gallium arsenide (GaAs) solar cell modules were embedded on the robot’s dorsum. By delivering time and region selective 808 nm laser illumination to the left and right photovoltaic panels, the bilateral muscle contraction sequences could be independently controlled without any physical tethering, enabling straight swimming, left/right turning, circular cruising, and U-turns. This approach requires no genetic modification of the biological tissue and significantly broadens the deployability of biosyncretic robots in aquatic environments.

Demonstration and analysis of the agile motion of the biosyncretic ray（Image by SIA）

Benchmark tests demonstrate multiple mobility breakthroughs. The robot achieved an average straight line swimming speed of 0.54 body lengths per second (BL s⁻¹, approximately 2.7 cm s⁻¹), with an instantaneous peak speed of 2 BL s⁻¹ —the highest relative forward speed ever reported for a skeletal-muscle-driven biosyncretic robot. Its minimum turning radius was only 0.8 body length, with a maximum turning angular velocity of 21° s⁻¹, enabling a full circular trajectory in only 17 seconds. Beyond underwater locomotion, the robot is capable of surface cruising, carrying underwater payloads up to 5 g, and performing low‑speed curvilinear motion across rigid ground surfaces.

“For the first time, we have coupled native isolated skeletal muscle with a wireless optoelectronic neural‑stimulation system. Our work validates native muscle tissue as a high‑performance biological actuator,” commented Dr. ZHANG Chuang, a researcher at SIA. “This study establishes a new paradigm for next‑generation, wireless, high‑performance biosyncretic robots. The electrical‑stimulation parameter framework we established can also offer reference for in‑vitro muscle repair after nerve injury and dynamic tissue‑engineering culture platforms.”

“This highly maneuverable wireless biosyncretic underwater robot holds promise for applications such as shallow-water micro-environmental monitoring and low disturbance observation of aquatic organisms.” Zhang added.

Looking ahead, the team will focus on optimizing in vitro muscle culture strategies to extend lifespan, developing neuron like flexible thin film electrodes for more uniform activation, and integrating photovoltaic energy harvesting with onboard storage for self powered operation. The research was supported by the National Natural Science Foundation of China, the New Cornerstone Science Foundation, the Chinese Academy of Sciences, and other national programs.