NIMSs Atomic Force Probe
<p>Jan 19, 2010 1:49 PM
 
atom by atom manip using
 
AFM  atomic force microscopy .
He is Spanish ... works in Japan and speaks Japanese;
freq modulation  AFM  vibrating cantilever.
arm is  225 by 38 by 7 nanos.
 
work in High vacuum like surface of moon.
 
picometer accuracy.
 
detect a shift on first mechanic resonant freq. as arm comes close to surface...
begin to see it at 5 angstr.
 
F tot =  F short range +  van der Waals  + electrostatic;
 
IBM  20 yrs ago at at Almaden  did the writing of IBM  using STM
but this had to be at 4 degr Kelvin  liq Helium.
 
Now he works at ROOM TEMP@!  
Manip Sn atoms on Si surface;  with AFM.
To do  120 manips takes 9 hours;   can write out  Sn  or Si in atoms...  stable for > 24 hrs.
 
Lateral interchange of  Ge and Cu on Si
 
now takes 1.5 hrs to write out Si.  See Nature article;
 
Q abt using atomic pencil for memory .???  slow.
Do chemical ID with AFM...  can detect and make and break covalent bonds  (1.5 A to 2 A).</p>