Bio-assemblies or Biomolecular Assemblies: containing several protein units, DNA loops, lipids, various ligands, etc. 


Biovorous: an organism capable of converting biological material into energy for sustenance.


Biochauvinism: The prejudice that biological systems have an intrinsic superiority that will always give them a monopoly on self-reproduction and intelligence.


BioMEMS -- biofunctionalised microelctromechanical systems used in medicine, that use microchips.


BioNEMS -- biofunctionalised nanoelectromechanical systems. 


Biomimetic: Imitating, copying, or learning from nature.


Biomimetic Materials: Materials that imitate, copy, or learn from nature. 


Biopolymeroptoelectromechanical Systems (BioPOEMS): combining optics and microelectromechanical systems, that can be used in biological applications. 


Biostasis: A condition in which an organism's cell and tissue structure are preserved, allowing later restoration by cell repair machines.


Blue Goo - opposite of Grey goo. Benificial technology, or "police" nanobots. 


Born-Oppenheimer Approximation: permits the use of classical quantum mechanics in modeling and thinking about molecular and atomic motions.


Bottom Up: Building larger objects from smaller building blocks. Nanotechnology seeks to use atoms and molecules as those building blocks. The advantage of bottom-up design is that the covalent bonds holding together a single molecule are far stronger than the weak.  Mostly done by chemists, attempting to create structure by connecting molecules. 


Brownian Assembly: Brownian motion in a fluid brings molecules together in various position and orientations. If molecules have suitable complementary surfaces, they can bind, assembling to form a specific structure.


Brownian Motion: Motion of a particle in a fluid owing to thermal agitation, Brownian motion plays a vital role in the assembly and activity of the molecular structures of life.


Bulk technology: Technology in which atoms and molecules are manipulated in bulk, rather than individually. 


Bucky Balls [AKA: C60 molecules & buckminsterfullerene] - molecules made up of 60 carbon atoms arranged in a series of interlocking hexagonal shapes, forming a structure similar to a soccer ball.


Bush Robot: A concept for robots of ultimate dexterity, they utilise fractal branching to create ever-shrinking "branches," eventually ending in nanoscale "fingers."