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Bioinspired Simultaneous Changes in Fluorescence Color, Brightness and Shape of Hydrogels Enabled by AIEgens

submitted on 18.09.2019, 12:17 and posted on 23.09.2019, 16:07 by Zhao Li, Xiaofan Ji, Junyi Gong, Yubing Hu, Wenjie Wu, Xinnan Wang, Hui-Qing Peng, Ryan Tsz Kin Kwok, Jacky W. Y. Lam, Ben Zhong Tang
Development of stimuli-responsive materials with complex practical functions is significant for achieving bioinspired artificial intelligence. It is challenging to fabricate stimuli-responsive hydrogels showing simultaneous changes in fluorescence color, brightness and shape in response to one stimulus. Herein a bilayer hydrogel strategy was designed by utilizing an aggregation-induced emission luminogen (AIEgen) tetra-(4-pyridylphenyl)ethylene (TPE-4Py) to fabricate hydrogels with the above capabilities. Bilayer hydrogel actuators with ionomer of poly(acrylamide-r-sodium 4-styrenesulfonate) (PAS) as matrix of both active and passive layers and TPE-4Py as the core function element in the active layer were prepared. At acidic pH, the protonation of TPE-4Py led to fluorescence color and brightness changes of the actuators and the electrostatic interactions between the protonated TPE-4Py and benzenesulfonate groups of PAS chains in the active layer caused the actuators to deform. The proposed TPE-4Py/PAS-based bilayer hydrogel actuators with such responsiveness to stimulus provide pregnant insights in the design of intelligent systems and are highly attractive material candidates in fields of 3D/4D printing, soft robots and smart wearable devices.


the National Science Foundation of China(21788102, 21490570 and 21490574)

the Research Grant Council of Hong Kong (16308116, 16305618 and C6009-17G)

the Science and Technology Plan of Shenzhen (JCYJ20160229205601482, JCY20170307173739739 and JCYJ20170818113602462)

the Innovation and Technology Commission (ITC-CNERC149C01)


Email Address of Submitting Author


The Hong Kong University of Science and Technology



ORCID For Submitting Author


Declaration of Conflict of Interest

The authors declare no competing financial interest.