Affiliation:
1. Research Center for Novel Computing Sensing and Intelligent Processing Zhejiang Lab Hangzhou 310000 China
2. General Surgery Department Children's Hospital National Clinical Research Center for Children's Health Zhejiang University School of Medicine Hangzhou 310052 China
3. Research Center for Frontier Fundamental Studies Zhejiang Lab Hangzhou 310000 China
4. State Key Lab of Extreme Photonics and Instrumentation College of Optical Science and Engineering Zhejiang University Hangzhou 310027 China
5. Key Laboratory of Intelligent Manufacturing Quality Big Data Tracing and Analysis of Zhejiang Province China Jiliang University Hangzhou 310018 China
Abstract
AbstractDeveloping stimulus‐responsive materials (SRMs) with reversible, large, and reprogrammable multi‐responsiveness is crucial for soft actuators and intelligent devices, which remains challenging. In this study, regenerated silk fibroin with hierarchical structure is utilized to specially design a reprogrammable multi‐stimuli‐responsive protein film and versatile soft actuators. The freestanding fibroin films exhibit notable thermal contraction (−1383 ppm K−1) and humidity‐responsiveness that can be repeatedly regulated by easy post‐treatment with Ca2+ as desired. The actuating and regulating mechanisms involve reversible conformational change that is magnified into macroscopic deformations by hierarchical structure, and the roles of material structure and ambient conditions in determining actuating performances are analyzed based on thermodynamics. Driven by humidity gradient, the fibroin film demonstrates spontaneous flipping locomotion, self‐oscillation with tunable frequencies, bio‐butterfly wing flapping, and transformation from 2D to 3D structure. Moreover, reprogrammable deformations at specific regions are achieved in multi‐stimuli‐driven PET/fibroin film actuators owing to the straightforward Ca2+‐content‐based tunability of the responsiveness. The fibroin‐based actuators can be used as artificial muscles to drive the high‐frequency wing‐flapping of a bio‐dragonfly and soft gripper to grasp, lift, and transfer objects. The simple yet effective strategy presented herein provides valuable inspiration for designing advanced SRMs and soft actuators with reprogrammable multi‐responsiveness.
Funder
National Natural Science Foundation of China
Key Research and Development Program of Zhejiang Province