Transcript of Electromechanical oscillators Alfredo D. Bobadilla.
- Slide 1
- Electromechanical oscillators Alfredo D. Bobadilla
- Slide 2
- An element of the electrical circuit experiences movement or
oscillations. Notice how the electrical current depends on the
capacitor displacement. In the system shown, the electrical
behavior depends on mechanical properties. What is an
electromechanical oscillator (or resonator) ?
- Slide 3
- Schematic of the gyros mechanical structure. Photograph of
mechanical sensor. The ADXRS gyros include two structures to enable
differential sensing in order to reject environmental shock and
vibration. Acceleration sensors for automobile air bag control
Gyroscopes for automobile driving control Pressure sensors for
blood, tire, etc. Commercialization of micro electromechanical
oscillators
- Slide 4
- Other applications 100x power reduction 100x size reduction 10x
improvement in spectral eff. & BW Wireless communication AFM
AFM images of DNA-based nanostructures 165nm scale bars = 100nm
Mechanical resonators as filters in RF circuits
- Slide 5
- The carbon nanotube electromechanical oscillator A tunable
nanoscale resonator V. Sazonova et al., Nature (2004). When a
voltage is applied between the tube and the underlying plate,
electrostatic force attracts the tube to the plate. An alternating
voltage sets up vibration as the tube is alternately attracted and
repelled. A static voltage applied at the same time increases the
tension on the tube, changing its frequency of vibration just as
tightening or loosening a guitar string changes its pitch. The
entire assembly of tube and plate behaves as a transistor, so the
tube's motion can be read out by measuring the current flow.
- Slide 6
- The carbon nanotube electromechanical oscillator B. Witkamp et
al, Nano Lett., 2006. J. Chung et al, Langmuir, 2004. Fabrication
process Dielectrophoretic assembly
- Slide 7
- The carbon nanotube electromechanical oscillator B. Witkamp, M.
Poot, and H. S. J. van der Zant, Nano Lett., 2006. Theoretical
framework
- Slide 8
- Mass spectrometer: Ultra high surface/volume ratio excellent
surface collection Ultra small mass exploit f o sensitivity to mass
loading Massive array very wide dynamic range Calorimeter: Ultra
low thermal capacity exploit f o sensitivity to T Massive array
extends linearity to very wide dynamic range Ultra small size very
fine pixel size as IR imager Performance improvement at
nanoscale
- Slide 9
- Slide 10
- THANKS!
- Slide 11
- G2 Rebuttal: Nano electromechanical oscillators Alfredo
Bobadilla
- Slide 12
- Comment: Did not describe the theoretical part of the
presentation Answer: The theoretical part was explained during the
lecture. In essence, the beam equation (classical mechanics) is
still useful for analyzing bending-mode vibrations in a carbon
nanotube longer than ~0.5um. Research work in the nonlinear regime
and the quantum regime has just began very recently. Comment: Text
was small and hard to locate on each slide Answer: Ill improve that
next presentation. Comment: current or potential applications of
such nano electromechanical oscillators should have been shown
Answer: The potential applications of nano electromechanical
oscillators is shown in the slides and was described during the
lecture. It was shown nanotube resonators can be incorporated as
the sensing element for improving the performance in mass
spectrometry and in calorimetry. Nano electromechanical oscillators
Rebuttal Alfredo D. Bobadilla
- Slide 13
- G1 Electro-Mechanical Oscillators Review Edson P. Bellido
Sosa
- Slide 14
- The presenter describe how a EM oscillator works and the basic
equations that rules its movement. He explain how a change in a
parameter, lets say the voltage on the system, can affect the
overall functioning of the device, and how researcher are taking
advantage of these behavior to fabricate consumer devices
- Slide 15
- He has explained the fabrication process and how a carbon
nanotube based oscillator works, and how they can tune the bending
mode vibration by changing the gate applied voltage and how they
can measure the bending modes using changes in the conductivity of
the carbon nanotube A comparison of the carbon nanotube oscillator
and the current oscillator used on the industry, in terms of
performance and cost would have been helpful. Further research is
needed specially in the large scale integration process since there
is no an high throughput technique to create arrays of carbon
nanotube oscillators and other nano- devices.
- Slide 16
- G3 Review: Electromechanical Oscillators By Mary Coan
2/12/2010
- Slide 17
- Review Overall the presentation was decent Described Current
applications of EN oscillators CNT EM oscillator using various
sources and diagrams Improvements to the performance Did not
describe the theoretical part of the presentation Showed many
equations with out listing parameters No physical description of
the diagrams
- Slide 18
- Review Overall style of the Presentation was lacking Text was
small and hard to locate on each slide Some of these things may
have been addressed during the actual presentation. However just
looking at the presentation online I had a hard time understanding
what each slide represented and the contents of each slide.
- Slide 19
- G4 Summary and review Electromechanical oscillators Diego A
Gomez-Gualdron
- Slide 20
- An electromechanical oscillator circuit The distance between
the plates of the capacitor varies with time, therefore changing
the capacitance, which in turn affect the behavior of the circuit
giving it an oscillatory behavior Figure.1
- Slide 21
- Promising application of a nanotube in a nanocircuit A voltage
in generates a charge in As a result the nanotube is pushed
downwards. Bending the nanotube alter the charge once again, ending
up in oscillatory motion with a frequency depending on the tension
forces in the nanotube. The oscillatory motion of the nanotube,
alterates the capacitance in cyclic-fashion analogous to the
macroscale circuit in the fig 1. Nature 431, 284-287 (16 September
2004) | doi:10.1038/nature02905
- Slide 22
- Additional Review A number of applications were shown for
electromechanical oscillators. However, I am not sure if the scale
of those examples is in the nanorange. If so, current or potential
applications of such nano electromechanical oscillators should have
been shown.
- Slide 23
- G5 Review Electromechanical Oscillators by Norma Rangel
- Slide 24
- Electromechanical oscillators by Alfredo D. Bobadilla Alfredo
show the basic concepts of electromechanical oscillators, with
examples of how these devices are being implemented in current
technologies in the market, alternative applications and a couple
of papers about state of the art electromechanical oscillators
using nanotubes and origami DNA. My suggestion for Alfred
presentation is to put more emphasis on the experimental work than
being too deep on the theoretical framework
- Slide 25
- G6 Review Electromechanical Oscillators by Jung Hwan Woo
- Slide 26
- Review Overall, the presentation needs improvements Improved
presentation skill will help deliver the idea in a more effective
manner The use of larger fonts and images will make it easier for
the audience to better visualize and understand the concept A
better introduction may attract the audience into the subject and
the presentation. The pace can be increased to contain more
information. The information on the subject was a bit too little
for a 30-minute presentation Jung Hwan Woo
- Slide 27
- Application What NEMS applications are there, which take
advantage of the electromechanical oscillator other than the carbon
nanotube application? What are the advantage of reducing the size
of the device in MEMS/NEMS applications? Is there any downside to
it? Jung Hwan Woo