Transcript Data Storage

Data Storage. Example: Advancement of the iPod
10 GB
2001
20 GB
2002
40 GB
2004
80 GB
2006
160 GB
2007
Hard drive
Magnetic data storage
Uses nanotechnology!
NANOMAGNETS:
Magnets are used to store data
Current
S
‘0’
?
N
Magnet with unknown magnetic state
Current
N
‘1’
S
Magnetic Data Storage
A computer hard drive stores your data magnetically
“Read”
Head
“Write”
Head
Signal
S
N
N
S
0
1
current
Disk
0
0
1
0
0
1
direction of disk motion
1
0
_
_
“Bits” of
information
Scaling Down to the Nanoscale
Increases the amount of data stored
on a fixed amount of “real estate” !
Now ~ 100 billion bits/in2, future target more than 1 trillion bits/in2
25 DVDs on a disk the size of a quarter, or
all Library of Congress books on a 1 sq ft tile!
Hard Disk Drives - a home for bits
Hitachi
Improving Magnetic Data Storage Technology
• The UMass Amherst Center for Hierarchical
Manufacturing is working to improve this technology
coil
1 bit
Perpendicular
Write Head
Granular Media
Soft Magnetic UnderLayer (SUL)
Y. Sonobe, et al., JMMM (2006)
• CHM Goal: Make "perfect" media
using self-assembled nano-templates
• Also, making new designs for storage
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Electrodeposited Nanowires in a
Nanoporous Polymer Template (Mask)
1x1012 wires/in2
nanoporous template
nanowires
in a
polycarbonate
filter
nanowires
in a diblock
copolymer
template
Binary Representation of Data
one bit
“1” or “0”
only 2 choices
two bits
00, 01, 10, 11
4 choices
three bits
000, 001, 010, 011,
100, 101, 110, 111
8 choices
n bits has 2n choices
For example, 5 bits has 25 = 32 choices...
more than enough to represent all the letters of the alphabet
Binary representation
of lower case letters
Character "SS"code
5-bit "Super Scientist" code:
ex: k = 01011
1
0
1
1
S
N
OR
S
N
N
N
S
N
S
S
0
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
y
z
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
01011
01100
01101
01110
01111
10000
10001
10010
10011
10100
10101
10110
10111
11000
11001
11010
(Coding Activity: Use attractive and repulsive forces to "read" the magnetic data!)
NEW! Multi-State Representation of Data
"CLUSTERS"
“Read”
Head
“Write”
Head
3
2
1
0
Disk
1
0
3
=
2
0
=
1
direction of disk motion
3-Nanomagnet Cluster
Imaged with a MFM
(Magnetic Force Microscope)
M = -3
M = -1
M = +1
M = +3
Just accomplished summer 2007 in the CHM!
"Multi-state" representation
of lower case letters
0
1
2
3
What is the word?
——————
Character "SS"code
a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
x
y
z
001
002
003
010
011
012
013
020
021
022
023
030
031
032
033
100
101
102
103
110
111
112
113
120
121
122