| 摘要 |
A novel miniaturized and highly automated method for the controlled printing of large arrays of nano- to femtoliter droplets is presented by actively transporting mother droplets over hydrophilic-in-hydrophobic micropatches. The proposed technology consists of single plate or double-plate devices where mother droplets can be actuated and hydrophilic-in-hydrophobic micropatches on one or both plates of the device where nano- to femtoliter droplets are printed. Due to the selective wettability of the more wettable hydrophilic micropatches in a hydrophobic matrix, large nano- to femtoliter droplet arrays are created when mother droplets are transported over these arrays. The parent droplets can be moved by different droplet actuation principles, for example by using the principle of electrowetting-on-dielectric droplet actuation. We propose another method that uses two plates that are placed on top of each other while being separated by a spacer. One plate is dedicated to confining and guiding of parent droplets by using hydrophilic patches in a hydrophobic matrix, while the other plate contains hydrophilic-in-hydrophobic arrays dedicated to the printing of nano- to femtoliter droplets. When the plate dedicated to parent droplet guiding is rotated over the plate dedicated to printing of nano- to femtoliter droplets, nano- to femtoliter droplets are dispensed inside the hydrophilic-in-hydrophobic array due to their selective wettability. All these proposed methods allow the parent droplets to be moved over the hydrophilic-in-hydrophobic arrays many times, providing unique advantages for performing bio-assays or miniaturized materials synthesis in nano- to femtoliter sized droplets. Upon the controlled evaporation of the dispensed droplets of solution, large arrays of the printed material can be generated on an automated way in seconds of time on a very flexible way. The method disclosed herein provides a distinct nano- to femtoliter droplet printing technique for a wide variety of applications such as protein- or cell-based bio-assays or printing of crystalline structures, suspensions of nanoparticles or components for microelectronics. |
