Fabrication Of Bio-Inspired Intelligent Structure Color Hydrogels And Their Applications In Flexible Sensors

Structural color,which is caused by the interaction between the periodic micro-/nanostructures and the incident light,is a widely existed optical phenomenon in nature.Inspired by this phenomenon,many biomimetic structural color materials have been developed.Among them,the intelligent structural color hydrogel materials constructed based on intelligent responsive polymers are imparted with unique optical sensing abilities due to their internal crystal lattice can undergo structural changes under external stimuli.Thus,they have huge research value in the field of flexible sensors.The flexible sensors are a type of device with signal sensing functions constructed of flexible materials with brilliant flexibility and ductility,various structures,and multi-signal monitoring abilities.However,most of the reported feedback signals output by flexible sensors after detecting external stimuli require data reading and analysis with the help of complex instruments and equipment,which greatly limits their application scenarios and scope.Therefore,constructing flexible sensors based on intelligent biomimetic structural color hydrogel materials to can take advantage of the material’s optical response characteristics under stimulation,and provide flexible sensors with output signals that are easy to detect and can be recognized by the human eyes.This paper mainly elaborates the research of intelligent biomimetic structural color hydrogel materials in flexible sensors.I developed a bilayer structure color hydrogel with an opal-inverse opal hybrid structure,constructed a flexible temperature sensor with dual response to ambient temperature,and further explored the application of the bilayer structure color hydrogel in the field of soft actuators.The specific work content is as follows:(1)Preparation of bilayer structural color hydrogel: Silica nanoparticles of different sizes are fabricated.Photonic crystal templates with structural colors are fabricated by blade coating.Structural color hydrogels with inverse opal structure were prepared by template replication method.The double-layer color hydrogels with opal-inverse opal hybrid structure were prepared by the secondary glue-pouring method.The structure and optical properties of the double-layer color hydrogels were investigated.(2)Temperature sensor based on bilayer hydrogel: An anisotropic bilayer structural color hydrogel temperature sensor with both thermal actuating and temperature response was prepared.The optical sensing function and deformation feedback function of the bilayer hydrogel under temperature stimulation were investigated,and the performance of the double-layer color hydrogel in various environments was tested.(3)Application exploration of soft actuator based on bilayer hydrogel: The bilayer hydrogel is used as a soft actuator to realize the capture and release of the ball.On this basis,graphene oxide was added into the bilayer hydrogels to prepare the intelligent structure color soft actuator with photothermal response characteristics,which could grasp,move and release the ball under the remote control of near-infrared light,providing a new research idea for the development of soft robot based on the intelligent structure color hydrogels.