Multiple Shape Manipulation of Azobenzene-Containing Polyimide by Combining Shape Memory Effect, Photofixity, and Photodeformation

The integration of different shape manipulation could greatly expand the versatility and functionality of smart materials, for which the achievement of synergism of different shape control is crucial. Here, we seek to create one kind of polyimide with integrated multiple shape manipulations by constructing the chemical network bearing azobenzene as a side chain. Trifunctional cross-linkers serving as net points of the chemical network render polyimide thermal-induced shape memory effects, which enables shape transformation. Azobenzene as a photoresponsive group is employed to achieve the photofixity and reversible photodeformability. Such photosensitive behaviors are independent of molecular prealignment and remain available after thermally shaping and fixing. As a result, these noninterfering performances induced by heat and light allow us to arbitrarily combine them to meet different needs. By integrating different shape manipulations, various shape changes and functional execution are conveniently achieved. The combination of the shape memory effect with photofixity enables the setting of diverse shapes, while the merging of it with reversible deformation facilitates the construction of actuators capable of executing functions. This study provides a new approach for the preparation of multifunctional actuators and has potential applications in the field of intelligent drivers.