Nanomechanical Systems: Toward Single-Molecule, and Single-Quantum Measurements
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Date: 05-18-2006
Start Time:
4:00pm
End Time: 5:00pm
Speaker: Michael L Roukes
From:
California Institute of Technology
Location: Interschool Lab, 7th floor, Schapiro/CEPSR
Hosted by:
Center for Integrated Science
Abstract:
Advanced techniques in nanoscience now enable the creation and
measurement of ultrasmall mechanical devices. These
nanoelectromechanical systems (NEMS) offer unprecedented opportunities
for sensing and quantum measurements. I will describe several specific
applications of NEMS that we are currently pursuing: vacuum-based force
sensing, single-molecule mass spectrometry, fluid-based biochemical
force assays for single-molecule molecular recognition, and
number-state measurements of single quantum jumps in a NEMS device at
ultralow temperatures.
The first two applications employ ultraminiature mechanical devices
that offer sensitivity down to the single-molecule limit. Their reduced
size yields extremely high fundamental vibrational frequencies while
simultaneously preserving very high mechanical responsivity. For
vacuum-based applications this powerful combination of attributes
translates directly in to high force and mass sensitivity – in the near
future we should attain the zeptonewton force regime and single Dalton
(1 amu) mass levels, respectively. In fluidic media, even though the
high quality factors attainable in vacuum become precipitously damped,
the small device size and high compliance still yields response below
the piconewton level – roughly the force required to break individual
hydrogen bonds within a macromolecule. Finally, single-quantum
experiments involve ultrasensitive measurements on high frequency
devices while avoiding linear coupling – a novel class of measurements
anticipated years ago, but not yet realized with mechanical systems.