Fabrication of fluorescent surface relief patterns using AIE polymer through a soft lithographic approach

Design of Collective Motions from Synthetic Molecular Switches, Rotors, and Motors

Precise control over molecular movement is of fundamental and practical importance in physics, biology, and chemistry. At nanoscale, the peculiar functioning principles and the synthesis of individual molecular actuators and machines has been the subject of intense investigations and debates over the past 60 years. In this review, we focus on the design of collective motions that are achieved by integrating, in space and time, several or many of these individual mechanical units together. In particular, we provide an in-depth look at the intermolecular couplings used to physically connect a number of artificial mechanically active molecular units such as photochromic molecular switches, nanomachines based on mechanical bonds, molecular rotors, and light-powered rotary motors. We highlight the various functioning principles that can lead to their collective motion at various length scales. We also emphasize how their synchronized, or desynchronized, mechanical behavior can lead to emerging functional properties and to their implementation into new active devices and materials.

Fluorescent Holographic Fringes with a Surface Relief Structure Based on Merocyanine Aggregation Driven by Blue-violet Laser

Stability and integration are the goals for developing photonic devices. Spirooxazines have the property of photoinduced merocyanine-aggregation in polymer matrix, which can be applied to fluorescence emission and stable information storage. Although visible light coherent radiation with UV-assist has been used to achieve polarization-modulated holographic memory in spirooxazine doped PMMA films, the complexity of optical systems is increased and the aggregation ability of merocyanine is decreased. Here, we report that fluorescent holographic gratings with a surface relief structure can be inscribed in the film via sole irradiation of 403.4 nm. Time-dependent photo-anisotropy and holographic dynamics were both investigated with different power densities of the near-UV laser. The non-exponential photokinetics was explained by the sequential formation of mono- and aggregate-merocyanine molecules. The appearance of merocyanine aggregates is found to be beneficial to the long-term holographic memory with fluorescent emission. This work provides a research strategy for the integrity of storage, display and micro-fabrication of organic functional-devices.