(Note to staff: Discuss and edit! - Hagalaz)

Two main approaches are used in nanotechnology. In the 'bottom-up' approach, materials and devices are built from molecular components which assemble themselves chemically by principals of molecular recognition, or material is deposited using an atomic force microscope to gradually build up a larger construct. In the 'top-down' approach, nano-objects are constructed from larger entities by removal of material or by physically moving individual atoms or molecules using a atomic force microscope.

Wet nanotech, or bionanotech, constructs are assembled using DNA, self-assembling protein molecules, and/or gengineered viruses. It is referred to as 'wet' because water is required as the working medium where the building process occurs inside an assembler. These assemblers can produce robots on a nanotech scale, bottom-up, that structurally resemble bacteria. These bionanomachines can be introduced into a patient's bloodstream to provide medical treatments and effect 'soft' changes, altering skin or blood cell production, production of specific proteins, or editing genetic material in reproductive organs, and are designed to 'die' after a set period of time.

Bionanotech cannot be used to effect 'hard' changes, such as reshaping existing organs, muscle or bone. Medical bionanomachines can only survive in controlled conditions, and must be tailored for a particular subject, or risk being attacked by the host's immune system.

It was rumored that at one time, bionanomachines were manufactured that would have been capable of application against a general population, capable of causing massive cellular death, blindness, sterility, or causing the host to succumb 'hereditary' diseases. This technology is not currently possible.

Dry nanotech is usually carbon-based (but other elements can and have been used) and would be produced in an assembler, using either a 'top-down' or 'bottom-up' approach. While the resulting nanotech constructs produced by an assembler would be quite robust, for example, starship engines made of a single large sapphire, or the anchor tether for an orbital elevator, the actual production must occur inside a sterile laboratory environment to minimize risks of contamination (which would prevent nanoscale machines from functioning due to misshapen parts, and would affect the structural integrity of large constructs). At this time, dry nanobots cannot function outside of a controlled lab environment.