© 1999 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999

5.3.1.1 Dimple Size

The smallest possible feature, or "dimple size," on a metamorphic surface is defined by the minimum turning radius of the surface. In most designs, this radius is determined by the minimum lateral extent of the component blocks of which the surface is comprised. Considerations of radiation-induced structural failure in diamondoid materials and components¹⁰ suggest a minimum unit size L ~ 10 nm (Chapter 13), roughly the thickness of the cellular lipid bilayer membrane. A single 180° turn requires a minimum of two linear segments; the minimum structural turning radius is r_min = L / 2^1/2 ~ 7 nm at a 90° joint angle, giving a minimum metamorphic feature diameter of ~14 nm. In most practical systems, power and control access requirements necessitate turning radii several times larger than this theoretical minimum, perhaps ~40-50 nm. Such larger structures should still be able to physically manipulate even the theoretically smallest biological cells (which are ~40-50 nm in diameter⁵²⁷).

Last updated on 17 February 2003