Fluorescent ionic liquid micro reservoirs fabricated by dual-step E-beam patterning

•Room temperature ionic liquids with fluorescent features are studied.•Electron beam is used for patterning thin films of liquid.•Fluorescence is strongly reduced by electron beam treatment.•Ionic liquid can be sealed in micro reservoir by the use of special pattering process.•Sealing the liquid is beneficial for maintaining its fluorescent characteristics. [Display omitted] In this work the fabrication of fluorescent microstructures through the e-beam induced solidification of two types of room temperature ionic liquids (RTILs) with fluorescent organic dyes is reported. It is shown that, by introducing dual-step e-beam patterning method with controlled accelerating voltage, solid micro-sized reservoirs are fabricated with liquid phase RTIL sealed inside. The presence of liquid inside the containers is confirmed by measuring their fluorescence spectra and comparison with results obtained for solid RTIL. The impact of the electron dose (ED) used in the exposure process on robustness and fluorescence characteristics of the fabricated structures is investigated. The temperature response of the micro reservoirs is also examined. The advantage of liquid – filled micro reservoirs is that they remain highly fluorescent, while solid RTIL structures exhibit significant fall in fluorescence ability associated with e-beam exposure damage.