Light-Responsive Shape Memory Polymer Network Containing Azobenzene: Shape Manipulation, Mechanical Regulation, and Intelligent Lubrication

Light-responsive materials have garnered significant atten-
tion in fields such as robotics and actuators due to their flexibility in
remote and localized control, presenting immense application potential. In
this work, we demonstrate intelligent responsive applications through the
introduction of a liquid crystal network formed by azobenzene, showcasing
photoinduced shape memory performance, light-reversible tribological
behavior, and thermally driven force modulation. By copolymerizing the
liquid crystal monomer 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-
methylbenzene with a functional azobenzene monomer, we can adjust the
cross-linking density and mechanical properties of the yield liquid crystal
elastomer networks (LCNs) by varying the azobenzene content, resulting
in a high-strength elastomer with a tensile strength of 23.6 MPa. The
unique microstructure of this material, which readily crystallizes at low
temperatures, allows LCN-20 to generate a high actuating stress of ∼5.6 MPa when cooled from 15 °C to −45 °C, significantly
expanding its potential as an actuator. The presence of azobenzene enables photoisomerization, imparting reversible changes in the
surface contact angle and modulus. Additionally, the photothermal effect of azobenzene facilitates light-controlled shape memory
performance. By integrating the tunable surface and mechanical properties, the LCNs demonstrate reversible tribological switching
upon UV−visible light irradiation, significantly expanding their potential as smart adaptive materials. This work provides a heuristic
perspective for designing multiresponsive and performance-adjustable materials.