Bio-Inspired Adaptive Microplate Arrays:Preparation And Magnetically Tuned Optics

Sunlight is the important source of materials and energy on the earth.Through the evolution of billions of years,bio-system has developed efficient optic-material-energy conversion systems by utilizing limited optical active compounds and diverse optical microstructures,and the bionic optics deriving from that also become a hot cross area related to multiple subjects such as physics,chemistry,materials,biology and so on.As synthetic chemistry provides more and more compounds with unique optical properties,regulating optical properties by microstructures from the perspective of bionics is also significant.Inspired by the poplar leaf,whose reflectance of two sides are different,this study is aimed to utilise magnetic field driven PDMS with microplate arrays obtained by a soft molding method to modulate optical properties of the surface,i.e.reflectance and fluorescence.To be more specific,the microplates with strong magnetic response performed directional movements with the applied magnetic field gradient and the direction of the field lines,which provides possibility for adjustable optical properties.In the reflectance study,via glancing angle deposition,one side of the microplate was selected to be modified with gold of high reflectivity,and the other side remained as PDMS embedded with dark magnetic particles,thus showed the low reflectance.By changing the direction of the applied magnetic field,the microplates could be bent with the gold side or PDMS side facing up,thus switching the whole sample between high reflectivity state and low reflectivity state.In the fluorescence modulating study,a fluorescent dye was incorporated in PDMS to get the fluorescent sample with microarrays,after glancing angle deposition,similar to venetian blinds,the fluorescent intensity of sample could be continuously adjusted by changing the tilting angle of the microplates from perpendicular to almost parallel to the substrate,also was changing the area of substrate shielded by the microplates.This research has potential to be used in micro-optical devices and integrated display devices.