Development of Nanofluidic Thermoelectric Devices Using Two-Dimensional Materials

我们已经巩固了在透射电子显微镜下悬浮二维材料上制造纳米孔的核心技术。具体来说，我们展示了从亚纳米到5纳米的孔研磨，显示了孔尺寸的可控性。提出了一种多次钻孔工艺，并进行了试验，显示出出色的空间分辨率。对于每次钻孔，孔径可以控制在1纳米以内。通过在稍微不同的位置重复该过程，可以精确地塑造所需的孔形状。使用这种方法，我们已经创建了具有高圆度的亚5纳米孔。同时，我们已经构建了通过纳米孔芯片测量离子电流的流动系统，热源温度控制器和购买的热电评估电流计。可以精确地控制由纳米孔膜分离的储层中的温度。另一方面，基于Poisson-Nernst-Planck方程和Navier-Stokes方程建立了一个理论模型来预测我们系统的热电性能。结果表明，当特征双电层厚度接近孔半径时，功率密度达到最大值。这将通过选择合适的溶液条件来指导我们的实验设计。

We have solidified the core technique for nanopore fabrication on suspended two-dimensional materials under transmission electron microscopy. Specifically, we demonstrated pore milling from sub-nanometer to 5 nanometers, showing the controllability of the pore dimension. A multiple drilling process is proposed and tested showing outstanding spacial resolution. For each drilling the pore size can be controlled within one nanometer. By repeating the process at slightly different locations, the desired pore shape can be precisely sculpted. Using this method, we have created sub-5 nanometer pores with high circularity. In the meanwhile, we have constructed the flow system for ionic current measurements through nanopore chips, temperature controllers for heat source and purchased current meters for thermoelectric evaluations. The temperature in the reservoirs separated by the nanopore membrane can be precisely controlled. On the other hand, a theoretical model based on the Poisson-Nernst-Planck and Navier-Stokes equations has been constructed to predict thermoelectric performance of our system. It is shown that the power density reaches the maximum as the characteristic electric double layer thickness becomes close to the pore radius. This will guide our experimental design by selecting suitable solution conditions.