10 GB2001
20 GB2002
40 GB2004
80 GB2006
160 GB2007
Data Storage. Example: Advancement of the iPod
Hard driveMagnetic data storage
Uses nanotechnology!
NANOMAGNETS: Magnets are used to store data
?
Magnet with unknown magnetic state
Current
N
S
‘0’
S
Current
N
‘1’
Magnetic Data StorageA computer hard drive stores your data magnetically
Disk
N S
direction of disk motion
“ Write”Head
0 0 1 0 1 0 0 1 1 0 _ _
“ Bits” ofinformation
NS
“ Read”Head
Signalcurrent
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, orall 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
Granular Media
PerpendicularWrite Head
Soft Magnetic UnderLayer (SUL)
coil
Y. Sonobe, et al., JMMM (2006)
1 bit
• CHM Goal: Make "perfect" mediausing self-assembled nano-templates• Also, making new designs for storage
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
nanoporous template
nanowiresin a polycarbonatefilter
nanowiresin a diblockcopolymer template
Electrodeposited Nanowires in aNanoporous Polymer Template (Mask)
1x1012 wires/in2
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
Character "SS"codea 00001b 00010c 00011d 00100e 00101f 00110g 00111h 01000i 01001j 01010k 01011l 01100
m 01101n 01110o 01111p 10000q 10001r 10010s 10011t 10100u 10101v 10110w 10111x 11000y 11001z 11010
Binary representationof lower case letters
5-bit "Super Scientist" code:
ex: k = 01011
0 1 0 1 1
S
N
S
N
S
N
N
S
N
S
OR
(Coding Activity: Use attractive and repulsive forces to "read" the magnetic data!)
NEW! Multi-State Representation of Data
Disk
“ Write”Head
“ Read”Head
= =0 1
direction of disk motion
1 0 3 2
0
12
3
"CLUSTERS"
M = -3 M = -1 M = +1 M = +3
3-Nanomagnet ClusterImaged with a MFM
(Magnetic Force Microscope)
Just accomplished summer 2007 in the CHM!
Character "SS"codea 001b 002c 003d 010e 011f 012g 013h 020i 021j 022k 023l 030
m 031n 032o 033p 100q 101r 102s 103t 110u 111v 112w 113x 120y 121z 122
"Multi-state" representationof lower case letters
— — — — — —
10 32
What is the word?