Preparation And Performance Of Actuator Based On Inverse Opal With Wettability

Although the water-triggered bending behavior of bilayer films has been a wide concerned,conventional soft actuator cannot achieve more complex functions,such as stimulus-dependent coloration in soft actuator,which prevents their application.In order to solve the above problems,this thesis uses photonic crystals as carriers and bilayer directional bending structural color actuators were prepared based on the hydrophilic difference.The mechanism of the design involves optical diffractions in the fabricated periodic nanostructures,differences in the surface wettability and swelling rate,uses the infiltration and capillary evaporation of water to realize the spectral diversity of reflectance,and the enhancement of bending by gradient infiltration.The conversion of chemical energy to mechanical energy gives it application value in related fields.In this thesis,SiO₂ photonic crystal was used as the carrier,and the shape memory polymer that can respond quickly in water environment was used as the filling material to construct a photonic crystal actuator with inverse opal structure controlled by wettability.The photonic crystal actuator has both sensitive optical response and directional actuation behavior,which provided a basic model for the design of bionic components.First,the modified St?ber method was used to prepare silica microspheres with particle sizes of 190 nm,200 nm,215 nm,230 nm,250 nm,and 290 nm.The PEGDA-ETPTA inverse opal photonic crystal with water responsiveness was developed.Under the action of water,the PEGDA(600)-ETPTA with 290 nm microporous showed a very large reflection peak shift(560nm redshift to 840 nm).And due to the effect of one-sided water,the curvature of the PEGDA(600)-ETPTA inverse opal photonic crystal reached 0.6264 mm^-1 within 20 s,accompanied by the reversible change of the reflection spectra,which has a perfect development prospect in the field of actuators.Then,based on PEGDA of different molecular weights,PEGDA(600)/PEGDA(200)inverse opal photonic crystal actuators with different wettability and pore size were constructed.Due to the different infiltration response modes,permeable and impermeable areas are formed on Layer A and Layer B of the bilayer actuator,respectively.When the volume ratio was PEGDA(600)?PEGDA(200)=3?2,the BPCA-1 film produced the maximum bending curvature of 0.52 mm^-1 and the minimum bending time of 55 s.The recovery speed mainly depended on the evaporation rate of water.And the existence of the inverse opal microporous structure not only makes this process accompanied by reversible changes in the reflectance spectrum,but will also be more conducive to the occurrence of driving behavior.Finally,PETMP was mixed with PEGDA(600)and PEGDA(200)in a volume ratio of1?2,and the sulfhydryl-ene click chemistry reaction was initiated by UV to obtain PETMP-co-PEGDA(600)/PETMP-co-PEGDA(200)inverse opal photonic crystal actuator,which produced the bending curvature of 0.21 mm^-1 in 51 s,and accompanied by obvious color changes.According to the octopus-inspired design,a bionic underwater jack was constructed,which can be reused about 100 times,laying the foundation for the combination of photonic crystal and actuator.