Micro-dispensers on inkjet-printed, paper-based digital microfluidic device for gold nanorod synthesis reactions

다국어 초록 (Multilingual Abstract)

Digital microfluidics (DMF) has become an important tool that is useful for a wide range of liquid handling applications. Especially Paper DMFs has emerged as a simple and low-cost method to fabricate fluid manipulation devices. This paper presents an Inkjet-printed, paper-based digital microfluidic device with an accurate micro-dispenser developed for unequal droplet splitting. In this research, we developed a micro-dispenser using unequal droplet splitting, unlike most of the previous researches that were based on equal splitting. To characterize the micro-dispenser, the effects of the applied voltage and the sub-electrode geometry on the splitting performance are studied. The droplet size increased showing a linear behavior in the range of the applied voltage 180-340 Vpp while the frequency was 1.0 kHz. For the effects of the sub-electrode geometry the height and width factors were concerned. This part of the study illustrates that there is a linear relation between the area of the split droplets and the area of the sub-electrodes. This linear behavior allows for the selection of an appropriate size of the sub-electrodes to be actuated based on the desired volume of the droplet We performed a seed meditated gold nanorod synthesis on this inkjet-printed, paper-based device, which was possible to make different sizes of gold nanorods with aspect ratio 2.3, 18.9, 33.0 by controlling the volume of growth reagent amounts. We propose that this represents a breakthrough for DMF, possibility for high precision reactions on-chip by the Micro-dispensers. This simple, low-cost, precise device will be an attractive alternative to various chemical reactions at resource limited and educational fields.