A novel smart bionic actuator deformed upon the stimuli

Recently the research team led by Dr. HUANG Wenwen at the ZJU-UoE Institute published an article titled "Stimuli-responsive composite biopolymer actuators with selective spatial deformation behavior" in the PNAS.

Bio-inspired actuators are characterized by stimuli-responsiveness and deformability are extensively applied in various fields, such as artificial tissues, medical devices and diagnostics as well as intelligent biosensors. However, most deformable actuators are poorly bio-compatible and bio-degradable, thereby circumscribing their applications in the biomedical field.   

Scheme of the fabrication of thermo-responsive and ionic strength responsive SELP/CNF actuators

Dr. HUANG Wenwen et al. developed a bionic actuator system entirely out of biocompatible and biodegradable materials. This design is inspired from the hydration-dependent actuation of ice plant seed capsules. Stimuli-responsive genetically engineered silk–elastin-like proteins (SELPs) and cellulose nanofibers (CNFs) are combined to fabricate an actuator system that can respond effectively to physical and chemical stimuli. This SELP/CNF actuator can achieve programmable and reversible deformations in response to the stimuli. It offers an option for fields such as in vivo biomedical soft robotics and biomimetic devices where biocompatibility, biodegradability, biomedical signals recognition, and durability are remarkably desired.

The transformation process of the petal-shaped multilayer SELP/CNF actuators over time in 1M NaCl solutions at room temperature. The color of actuators was stained by water-proof inks.