Highly sensitive AIE-based mechanoresponsive luminescent polymer coatings for surface pressure imaging

Herein, we report on a facile methodology for the development of aggregation induced emission (AIE)-based mechanoresponsive luminescent (MRL) polymer coatings with the characteristics of high sensitivity and high reversibility in 2D surface pressure imaging. Amorphous nitro-functionalized tetraphenyethylene was embedded into an elastomer substrate to prevent the crystallization of the dye and meanwhile to allow the conformational variation in response to the gradual deformation and relaxation of the polymer network. The strategy endows strain-mediated fluorescence enhancement and fast recovery of the material in compressive force loading-unloading cycles. The relationship between pressure and fluorescence intensity of the AIE-based MRL coatings was calibrated which showed adjustable sensitivity within kilopascal (kPa) to megapascal (MPa) range, according to the mechanical property of the polymer matrix. The coatings were capable for the detection of surface pressure distribution through non-contact optical observation technique in both static and dynamic processes. The high sensitivity realized the utility of AIE-based materials in the field of hydrodynamics and probably for other applications in industry.