ULTIMATE COMPUTING - Quantum Consciousness Studies

NanoTechnology 211
Figure 10.18: STM-induced/detected molecular conformation change. By Paul
Jablonka (Schneiker and Hameroff, 1987).
10.6 STM/FMs and Biomedical Applications
Nondestructive STM interactions with biological material have immense
potential, assuming certain technical obstacles are overcome. Potential problems
include the following:
1. Biomolecules, cells, and tissues are not conductors. Electron tunneling
through these materials, if it occurs, may be damaging. Nevertheless, several
groups including IBM Zurich have succeeded in imaging biomaterials in air such
as protein coated DNA and virus structures. The tunneling is thought to occur
from tip onto biomolecular surface followed by “low resistance electron transport
to the conducting substrate” (Travaglini, Rohrer, Amrein and Gross, 1986).
Simultaneous optical microscopy, as can occur with the nanotech workstation,
may help this situation since photons can lower tunneling barriers. Appropriate
choice of optical microscopy wavelengths may thus facilitate STM imaging by
permitting non damaging tunneling currents.
An alternative approach is to utilize an atomic force microscope (AFM) mode
of operation for biological materials. In this case a lever arrangement adapted to,
and mounted on, an STM which trails along the surface, or is held steady to
observe mechanical dynamics of the material (i.e. protein conformational change).
The movement of the lever is monitored by the STM, so that mapping and
dynamics can be observed without direct tunneling through the biomaterial.