Continuous Scalable NanoManufacturing of 1D and 2D Semiconductors for Human Welfare

Microfluidic synthesis has been widely researched and reported as a scalable, controllable and continuous manufacturing approach for nanomaterials synthesis. However, while most of the studies focus on the synthesis of 0D nanomaterials, e.g., nanoparticles and quantum dots, few have reported 1D or 2D materials, let alone 1D or 2D semiconductors. Our study provided in-depth understanding on continuous and scalable 1D and 2D semiconductor manufacturing with droplet-based microfluidic synthesis. Leveraging previous knowledge on nanomaterials growth in batch process and with the help of data-driven approach, the influence of process parameters to the performance of the product is bridged.

We first looked into the synthesis of Te nanowire with systematic process parameters tuning. Utilizing a reconfigurable, droplet-based microfluidic platform with precise control over process parameters and chemical concentration, Te nanowire with dimensions comparable to that of batch process can be obtained. Data-driven fitting of the experimental data sketched better pictures on the influence of chemical concentration variation to the Te nanowire morphology and determines the key parameters in tuning the nanowire diameter. A comprehensive understanding of the effect of fluid dynamics to the materials growth inside the microfluidic channel, on top of our previous understanding, was augmented. We further expanded our horizons towards scalable 2D Te and telluride nanostructure manufacturing using microfluidic platform. Adapting the process and knowledge from batch synthesis, 2D tellurene and 2D Sb₂Te₃ nanoplates can be obtained. Boundary conditions of 2D nanostructure formation within microfluidic channel were identified to provide guidance on future design and synthesis of 2D semiconductors.

In addition to our findings in microfluidic growth of 1D/2D Te nanomaterials and 2D Sb₂Te₃ nanoplates, we further augmented the system into multi-stage setup, with each stage designed for different purposes. Leveraging the rapid heat transfer advantage of microfluidic synthesis, growth process can be precisely tuned with respect to nucleation stage and growth stage individually to decoupling nucleation and growth stage of nanomaterials synthesis. Our reconfigurable system could also achieve manufacturing and conversion Te nanowire into Ag₂Te nanowire in a single-flow setup, which requires a two-step process in traditional batch process.

With the successful synthesis of 1D/2D semiconductors using scalable approaches, including batch and microfluidic process, we explored potential applications of these materials in human health and energy. Te nanowire with its piezoelectric effect is a promising material for self-powered human pulse sensing, which can be used to monitor mental workload and stresses. On the other hand, piezoelectric ZnO nanorod, manufactured through batch synthesis, delivers significant boost in piezo-electrocatalytic artificial nitrogen fixation performance. Our explorations have shown huge potential of these nanomaterials in improving human welfare in health and energy aspects.

In sum, our research provided fundamental and systematic understanding of microfluidic synthesis of 1D/2D semiconductors that could be applied to other materials. We also explored various applications in human health related sensing and energy field, leveraging the materials’ unique properties to boost their performance. The knowledge obtained from the study will fill the gap of continuous and scalable synthesis of 1D/2D semiconductor materials using microfluidic approach and promote their applications in sensing and energy, while providing paths and guidelines for optimizing 1D/2D semiconductors design with respect to different applications.