We aim at the design, characterization, production and application of biological or biomimetic structures, devices and systems by controlling shape, size and properties at atomic, molecular and macromolecular scales, where the relevant physical phenomena differ significantly from those at larger size scales.
For example, gravity and acceleration forces, which are significant on a macroscopic scale, have a negligible effect on nanoscopic systems: The blood flow in large vessels is turbulent. In the tiny capillary veins, however, the blood flow is steady, and undisturbed by turbulences, as inertia forces are not effective at this size scale.
One practical example of bionanotechnology today is luminescent nanoparticles, which can be designed to target specific cells or cell components. This is very useful for marking the location of interesting molecules in a tissue sample, or body; and diagnosing diseases.