Programming a UV-Triggered In Situ Cospinning Fiber with Site-Specific and Anisotropic Deformation Behavior toward...

Fabric and textile actuators capable of displaying light-controlled morphing behaviors are of essential significance in nature and wearable devices. Despite several studies on this system, the precise regulation for performing combined programmable site-specific and light-controlled deformation remains a challenging issue. In this work, a dual-layer-based fabric actuator is fabricated via UV-triggered in situ electrospinning of polycaprolactone/polyethylene glycol (denoted as PCL/PEG) matrix coated with polydopamine (PDA) nanospheres. The method affords the resultant fiber actuator capable of exhibiting stretchable characteristic in cold-drawing environment while maintaining relatively decent morphing properties. Additionally, upon site-specific irradiation with laser spot, the surface resonance absorption of the coated PDA allows for the formation of temperature gradient in the fiber's strained state, enabling the fabric actuators with programmable on-demand out-of-plane bending deformations due to anisotropic chain relaxation and the release of embedded internal stress. Uniquely, by designing macroscopic bilayer structures with orientated molecular chain segments and vector sum of shape recovery forces, the fabric actuator exhibited bending and chiral twisting deformations as determined by the orientation angles between the upper and lower layer. The results presented in this study clearly provide insight on fabricating light-driven programmable fabric actuators.