Scalable Manufacturing of Nanogaps

The ability to manufacture a nanogap in between two electrodes has proven a powerful catalyst for scientific discoveries in nanoscience and molecular electronics. A wide range of bottom‐up and top‐down methodologies are now available to fabricate nanogaps that are less than 10 nm wide. However, most available techniques involve time‐consuming serial processes that are not compatible with large‐scale manufacturing of nanogap devices. The scalable manufacturing of sub‐10 nm gaps remains a great technological challenge that currently hinders both experimental nanoscience and the prospects for commercial exploitation of nanogap devices. Here, available nanogap fabrication methodologies are reviewed and a detailed comparison of their merits is provided, with special focus on large‐scale and reproducible manufacturing of nanogaps. The most promising approaches that could achieve a breakthrough in research and commercial applications are identified. Emerging scalable nanogap manufacturing methodologies will ultimately enable applications with high scientific and societal impact, including high‐speed whole genome sequencing, electromechanical computing, and molecular electronics using nanogap electrodes. Nanogap electrodes are essential components for cutting‐edge electronic, photonic, and mechanical applications in nanosciences and molecular electronics. Nevertheless, three fundamental manufacturing challenges currently hinder their implementation in next‐generation integrated electronic devices. The available nanogap manufacturing methodologies are reviewed and discussed and a roadmap for future development toward large‐scale nanogap manufacturing is proposed.