Real‐Time Force Monitoring of Electrically Stimulated 3D‐Bioengineered Muscle Bioactuators Using Organic Sensors with Tunable Sensitivity

The contractile nature of skeletal muscle tissue makes it especially attractive for powering biohybrid actuators. Significant efforts have been dedicated to the improvement and control of contraction force, going one step forward toward the automation of these biohybrid platforms. Herein, 3D‐bioengineered skeletal muscle tissues are integrated with organic transistor‐based sensors to define a soft bioactuator with real‐time force monitoring capabilities. The muscle tissue is electrically stimulated while the organic sensor ensures transduction of the exerted force into an electrical signal that allows direct monitoring of the bioactuator performance. Sensor calibration is carried out to define its sensitivity at different biasing conditions: as opposed to standard, two‐terminal piezoresistive devices, transistor‐based strain sensors show tunable sensitivity by acting on the voltage applied to a third terminal — the gate. A complete evaluation of sensing performances is provided, demonstrating that real‐time monitoring is effective under different conditions, including stimulation signal frequency and chemical modulation of the bioactuator contraction, demonstrating its potential use as a drug testing platform. In the reported results, the way is paved for a complete exploitation of organic devices in soft robotic applications and to the development of novel biohybrid machines in bioengineering and biomedicine.