Bio-nanotechnology is a scientific field combining principles of nanotechnology, engineering conducted on a nanoscale (under 100 nanometers), and biology, the study of living organisms. Bio-nanotechnology uses nanotechnology techniques, including imaging, x-ray diffraction, and statistical mechanics, to solve biological problems. Applications of bio-nanotechnology include nanobots, tiny robots used to direct chemotherapy to cancer cells thus minimizing side effects, and nanoparticles, manufactured vesicles used for drug delivery.