Rao Lanka Tata, Rewatkar Prakash, Dubey Satish Kumar, Javed Arshad, Goel Sanket
Department of Mechanical Engineering, Birla Institute of Technology and Science (BITS) Pilani, Hyderabad Campus, Hyderabad, 500078, India.
MEMS, Microfluidics and Nanoelectronics Lab, Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science (BITS) Pilani, Hyderabad Campus, Hyderabad, 500078, India.
Sci Rep. 2020 Jul 15;10(1):11675. doi: 10.1038/s41598-020-68579-x.
Graphite pencil stroked electrodes for paper-based Microfluidic devices are gaining immense attention due to their electrochemical properties, cost efficiency, and ease-of-use. However, their widespread use has been hindered by the challenges associated with their manual fabrication such as non-uniformity in graphite deposition, applied pressure, etc. This work presents the design and development of an automated graphite pencil stroking device for graphite electrode fabrication with high efficiency through a compact, inexpensive and automatic process, with reduced fabrication time and human intervention leading to more uniformity. The motion platform of Graphtec plotter was used to create multiple strokes with the help of the proposed device. Such inexpensive graphite electrodes (less than the US $1) have been observed to be porous in nature, acting as diffusion agents. The automated graphite electrodes were used to study the performance of microfluidic paper fuel cells (MPFCs) with formic acid, oxygen, and sulphuric acid acting as fuel, oxidising agent and electrolyte respectively. From this configuration, the maximum current density and power density were measured to be 1,305.5 µA cm and 135.5 µW cm, respectively at 0.3 V stable OCP at 100 strokes. Overall, the study enumerates the development of an automated pencil stroke device for fabricating graphite electrodes, which can potentially be harnessed in numerous miniaturized paper based applications.
用于纸质微流控装置的石墨铅笔划擦电极因其电化学性能、成本效益和易用性而备受关注。然而，其广泛应用受到与手工制作相关的挑战的阻碍，如石墨沉积不均匀、施加压力等。这项工作展示了一种用于制造石墨电极的自动石墨铅笔划擦装置的设计与开发，该装置通过紧凑、廉价且自动的过程实现高效制作，减少了制作时间和人工干预，从而提高了均匀性。利用Graphtec绘图仪的运动平台，借助所提出的装置进行多次划擦。已观察到这种廉价的石墨电极（成本低于1美元）本质上是多孔的，可作为扩散剂。使用自动石墨电极研究了微流控纸质燃料电池（MPFC）的性能，其中甲酸、氧气和硫酸分别作为燃料、氧化剂和电解质。在此配置下，在100次划擦、0.3 V稳定开路电位时，测得的最大电流密度和功率密度分别为1305.5 μA/cm和135.5 μW/cm。总体而言，该研究阐述了一种用于制造石墨电极的自动铅笔划擦装置的开发，该装置有望应用于众多基于纸张的小型化应用中。
