High-performance nano-biocomposite ionic soft actuators based on microfibrillated cellulose/ionic liquid electrolyte membrane

High-performance electro-responsive ionic soft actuators with low actuation voltage, large bending strain, and ecofriendly functionalities have received great interest in soft robots, biomimetic robots, biomedical devise, flexible electronics, and wearable devices. Herein, we report a novel ionic soft actuator using biofriendly microfibrillated cellulose (MFC) and PEDOT:PSS, which exhibited a large peak-to-peak displacement (11.21 mm) mm under a sinusoidal excitation of 1.5 V at 0.1 Hz, low actuation voltage, wide driving frequency, excellent actuation durability (98% retention for 2 h), and excellent controllability, due to the strong ionic interactions of MFC fibers with cations and anions of ionic liquid (IL). Furthermore, the helical MFC-IL ionic actuator was successfully designed, displaying that the radical displacements of the helical actuator could be controlled by changing the applied frequency and voltage. Therefore, the proposed ionic actuator as well as its helical design will offer an available pathway for guiding the development of artificial muscles, biomedical active devices, soft robots, flexible electronics, and soft electronics.

Automated summary

This study presents a novel ionic soft actuator using biofriendly microfibrillated cellulose (MFC) and PEDOT:PSS, which exhibits low actuation voltage, large displacement, wide driving frequency, and excellent durability. The actuator's performance can be attributed to the strong ionic interactions between MFC fibers and the ionic liquid (IL). Furthermore, a helical design of the MFC-IL actuator is demonstrated, showing controllable radial displacements by adjusting the applied frequency and voltage.