08-01-2010, 06:07 PM
Nanoelectromechanical systems, or NEMS, are MEMS scaled to submicron dimensions. it is possible to attain extremely high fundamental frequencies while preserving very high mechanical responsivity. their extreme surface-to-volume ratios, and their unconventional characteristic range of operation are a challenge. ultrasensitive, very high bandwidth displacement transducers; an
unprecedented control of surface quality and adsorbates; novel
modes of efficient actuation at the nanoscale are all realisable with this technology.
Introduction
They have characters like fundamental frequencies in the microwave range; Qâ„¢s, i.e.
mechanical quality factors, in the tens of thousandsactive masses in the femtogram range; force
sensitivities at the attonewton level; mass sensitivity at the level of
individual molecules, heat capacities far below a yoctocalorie.
MULTITERMINAL MECHANICAL DEVICES
multiterminal electromechanical devices with two or more ports are possible mechanical
transducers provide input stimuli (i.e. signal forces), and read out a
mechanical response. either quasi-static or time-
varying electric signals can be applied, and then converted by the
control transducers into quasi-static or time-varying forces to
induce mechanical
reaction to perturb the properties of the mechanical element in a controlled,
manner.
NEMS Attributes
1) frequency:
Nanodevices in this ultimate limit will have resonant frequencies in
the THz range, which is the characteristic of molecular vibrations.
2)Quality Factor.
The Qâ„¢s attained for NEMS in are in the range from 10^3 to 10^5. . This
small degree of internal dissipation (D=1/Q) impart to NEMS their
low operating power levels and high attainable force sensitivity.
The Q's are much greater than the electrical resonators.
3)opertaing power level:
the total system power levels still are onlyof order 1 microWatt This is six orders of magnitude smaller than powerdissipation in current systems of similar complexity based upondigital devices that work solely in the electrical domain.
4)Available Dynamic Range
Full seminar report download:
[attachment=1118]
unprecedented control of surface quality and adsorbates; novel
modes of efficient actuation at the nanoscale are all realisable with this technology.
Introduction
They have characters like fundamental frequencies in the microwave range; Qâ„¢s, i.e.
mechanical quality factors, in the tens of thousandsactive masses in the femtogram range; force
sensitivities at the attonewton level; mass sensitivity at the level of
individual molecules, heat capacities far below a yoctocalorie.
MULTITERMINAL MECHANICAL DEVICES
multiterminal electromechanical devices with two or more ports are possible mechanical
transducers provide input stimuli (i.e. signal forces), and read out a
mechanical response. either quasi-static or time-
varying electric signals can be applied, and then converted by the
control transducers into quasi-static or time-varying forces to
induce mechanical
reaction to perturb the properties of the mechanical element in a controlled,
manner.
NEMS Attributes
1) frequency:
Nanodevices in this ultimate limit will have resonant frequencies in
the THz range, which is the characteristic of molecular vibrations.
2)Quality Factor.
The Qâ„¢s attained for NEMS in are in the range from 10^3 to 10^5. . This
small degree of internal dissipation (D=1/Q) impart to NEMS their
low operating power levels and high attainable force sensitivity.
The Q's are much greater than the electrical resonators.
3)opertaing power level:
the total system power levels still are onlyof order 1 microWatt This is six orders of magnitude smaller than powerdissipation in current systems of similar complexity based upondigital devices that work solely in the electrical domain.
4)Available Dynamic Range
Full seminar report download:
[attachment=1118]
