Nanobots are so tiny that up to 800 of them could fit across the width of a single human hair.

Nanotechnology operates at the nanoscale, defined as 1 to 100 nanometers. To put this in perspective, a single sheet of paper is about 100,000 nanometers thick. A human hair averages 80,000 to 100,000 nanometers in width, while modern nanobots are being engineered at sizes as small as 100 nanometers, meaning hundreds could span a single strand.In 2018, researchers at the University of New South Wales and other global institutions successfully demonstrated nanobots capable of carrying drugs to specific targets. These machines often utilize molecular motors or are controlled externally using magnetic fields. This precision is vital for oncology, where traditional chemotherapy often kills healthy cells alongside cancerous ones.Physics at the nanoscale is dominated by low Reynolds numbers, meaning viscosity is more significant than inertia. For a nanobot, moving through blood is like a human trying to swim through thick honey. Consequently, engineers look to nature for inspiration, designing bots with flagella-like tails similar to those found on bacteria like E. coli.Future applications being studied by organizations like the Max Planck Institute include non-invasive surgery and real-time internal health monitoring. By 2030, the nanomedicine market is projected to reach billions of dollars as these technologies move from laboratory trials to clinical reality. This field represents a fundamental shift from treating the whole body to repairing it at the atomic level.