Engineering Carbon Nanotube Fibers by a Mechanical Twisting Method Graduate Research Mentor, Ji Hao,...
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Transcript of Engineering Carbon Nanotube Fibers by a Mechanical Twisting Method Graduate Research Mentor, Ji Hao,...
Engineering Carbon Nanotube Fibers by a Mechanical Twisting
Method
Graduate Research Mentor, Ji Hao, Northeastern UniversityGary Hu, YSP Student, North Quincy High SchoolJames Zhou, YSP Student, Andover High School
Professor Yung Joon Jung, Mechanical and Industrial Engineering, Northeastern University
Carbon Nanotubes (CNTs)High tensile strengthStiffest material yet discoveredHigh strength to weight ratio
What’s the Problem?Current applications limitedStrength does not scaleManufacturing deformitiesPoor alignment
PurposeTo design a fiber twisting
apparatusTo compare mechanical
properties of twisted and untwisted fibers
To investigate the morphological effect of twisting fibers
Our FiberMicroscopic image of pristine CNT fiber (Diameter: ~800μm) (bottom left)SEM image inside small bundles of CNT (Diameter: ~10-100nm) (bottom right)TEM image of individual DWNTs and TWNTs (Diameter: ~5nm) (upper right)
STP-PWR-3204 (power source)
STP-DRV-405(micro-
stepping drive)
6221 SourceMeter(DC source)
DWNT/TWNT fibers
STP-MTR-17040(micro-
stepping motor)
AC 110V(outlet)
Computer with
LabVIEW2011 SP1
Schematic of the Motor Setup
Morphological Data
Larger twisting angles
Smaller diameter
Greater fraying
20 30 40 50 60
24
28
32
36
40 Twisting angle Diameter
Cycles
Tw
istin
g an
gle
of tw
iste
d C
NT
fibe
r (d
egre
e)
130
140
150
160
170
Dia
met
er o
f tw
iste
d C
NT
fibe
r (
m)
(b) The dependence of fiber diameter on the number of cycles
(a) The dependence of twisting angle on the number of cycles
Conclusion and Future WorkTwisted fibers have higher
performanceFraying and other defects limit
the extent of useful twistingImprove setupReduce deformitiesChange motor frequencyControl angle and diameter
individually
AcknowledgementsCenter for STEM EducationYoung Scholars Program & Team
Claire Duggan – DirectorMaureen Cabrera, Madeline Leger – YSP Coordinators
Yung Joon Jung – Advising professor
Ji Hao – Graduate student mentor
References
Kai Liu et al, Nanotechnology 21, 045708 (2010).
Yu MF et al, Science 287, 637–640 (2000).
Zhang M, Atkinson KR and Baughman RH, Science 306, 1358-1361 (2004).