Chinese Scientists Build Biohybrid Manta Ray Robot Powered by Frog Muscle
Chinese researchers at the Chinese Academy of Sciences have engineered a light-controlled biohybrid manta ray robot powered by intact frog muscle tissue, achieving untethered aquatic locomotion and precise maneuverability. According to a research paper published in Advanced Functional Materials titled “High-Mobility Wireless Light-Controlled Biosyncretic Manta Ray” and covered by Nanowerk Spotlight on August 20, 2026, the roughly 5-centimeter-long aquatic device relies on living biological actuators rather than conventional electric motors to drive its pectoral fins through water.
The Tech TL;DR:
- Core Architecture: A biohybrid manta ray robot driven by isolated gracilis muscles taken from Rana catesbeiana, overcoming the force limitations typically seen in engineered skeletal muscle tissues grown from cells.
- Control Vector: Onboard gallium arsenide solar cells convert an 808 nm laser beam into electricity, boosting voltage via a small circuit before platinum electrodes trigger muscle contractions via the nerve.
- Performance Metrics: At designated stimulation settings, the biological actuators produce approximately 6.5 N of force with a 25% shortening length, propelling the untethered device at an average speed of 0.54 body lengths per second.
Architectural Breakdown of Biosyncretic Aquatic Actuation
However, biohybrid systems leverage native living tissue to optimize power-to-weight ratios. As reported in the Nanowerk Spotlight breakdown of Qi Zhang’s team’s published findings, natural skeletal muscle maintains an organized cellular architecture capable of higher force output per gram than comparable synthetic micro-actuators. The structural chassis of the manta ray houses two isolated gracilis muscles from Rana catesbeiana, with each muscle anchored at one end to the body and at the other to a flexible pectoral fin.
Controlling these biological tissues in an aquatic environment introduces significant engineering hurdles. Radiofrequency signals attenuate rapidly underwater, and direct electric-field stimulation restricts operating envelopes. To bypass these constraints, the Chinese Academy of Sciences architecture employs an optoelectronic conversion loop. Gallium arsenide solar cells mounted dorsally capture an external 808 nm laser beam. The resulting photovoltaic current is stepped up through a localized micro-circuit and delivered via platinum electrodes directly to the muscle’s nerve, rather than stimulating the tissue fibres directly. This indirect neural activation preserves fine-grained differential control over each fin.
// Conceptual schematic of the optoelectronic signal pipeline
Laser Beam (808 nm)
--> Dorsal GaAs Solar Cells
--> Voltage Boost Circuit
--> Platinum Electrodes
--> Muscle Nerve
--> Fin Actuation (6.5 N Force, 25% Shortening)
Operational Dynamics and Kinematic Benchmarks
By pulsing the laser independently for the left and right dorsal solar arrays, the research team achieved varied kinematics. Dual-muscle simultaneous actuation drives the biohybrid platform forward in a straight vector, whereas alternating or biased pulse frequencies create differential thrust. This asymmetry steers the system through curves, tight turns, full circles, and immediate turnaround maneuvers in water.
Maintaining tissue viability without inducing rapid thermal or mechanical fatigue required careful tuning of the stimulation parameters. Continuous high-frequency pulsing forces the muscle into sustained contraction and rapid exhaustion. Consequently, the researchers established a controlled stimulation rhythm that balances high force delivery against cellular endurance.