Nanomedicine, Volume I: Basic Capabilities
© 1999 Robert A. Freitas Jr. All Rights Reserved.
Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999
Nanorobots will use clocks in many applications. Computer gating,* navigation, and high-speed sensor applications may require repeatable timing in the 1-1000 nanosec range, or 1-1000 microsec for lower-speed chemical and chemotactic sensing, although long-term clock stability is not especially critical for computing. Neuron-mediated signals and muscle motions are monitored and controlled on a 1-1000 millisec timescale, while conscious human action and most human biorhythms occur in the 1-105 sec range.
* Clocks are not strictly required for computation. D.E. Muller pioneered attempts1880,1881 in the late 1950s to eliminate all time dependencies in digital logic circuits, including fundamental mode circuits,1882 speed-independent circuits and delay insensitive circuits (generally considered the most difficult, expensive and elusive circuits to design1883). Traditional asynchronous control designs1884 employ considerably more circuitry than is required by a functionally equivalent clocked Boolean logic circuit; K.M. Fant and S.A. Brandt1885 have devised a more parsimonious and theoretically complete approach to delay insensitive circuits called Null Convention Logic.
This Section briefly introduces human chronobiology (Section 10.1.1), then describes possible nanoscale oscillator systems that could be useful in nanorobotic clocks (Section 10.1.2), basic principles of pre- and post-infusion nanorobot chronometer synchronization (Section 10.1.3), and dedicated chronometer organs (Section 10.1.4).
Last updated on 22 February 2003