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Nickel Sensors Could Raise Hard Disk Capacity
Makarand writes "Tiny filaments of nickel, thinner than a wavelength of visible light, acting as magnetic
sensors may expand the storage capacity of hard disks many times. Although, technologies
exist to increase hard disk capacity, reading data bits reliably from such disks has proven
difficult because as data bits become smaller their magnetic fields are weaker and difficult
to pick up. Nickel filaments are capable of picking up of these weak magnetic fields
using a phenomenon called "ballistic magnetoresistance" which is not completely understood.
As the sensors are only a few atoms wide the electrons travel along a straight line
in the conductor greatly enhancing the binary signal picked up from the data bits.
These sensors could also be used to detect biomolecules in low concentrations."
That depends on how many spins an atom can have at once:) Welcome to the world of quatum mechanics.
Spontaneous flipping still poses an upper limit to magnetic data storage capacity. Basically, if you cram lots of bits too close together, they will start flipping each other.
r ch.nsf/pages/frontier399.html
see: http://domino.watson.ibm.com/comm/wwwr_thinkresea
under storing information for info on pushing this limit
Visual light takes up just a small segment of the electromagnetic spectrum. There are shorter wavelengths they can use to detect it.
I agree. I think that the hard drive manufacturers need to stop focusing on how big they can make drives, and to start focusing on ways to make drives more reliable. A 200 GB drive is useless if it dies after six months.
"You spoony bard!" -Tellah
Using a Scanning Electron Microscope (SEM) or an Atomic Force Micoscope (AFM) would be my guess.
"It's comin' back around again..." -RATM
You can't do this for modern optical media because the size of the details of the media is close to the wavelengths of visible light itself. Once you get to that size, there IS no 'color', to speak of, since color is just the size of the wavelength itself. Conventional CD players use red or infrared lasers, I believe, which have a wide wavelength. DVD players on the other hand, use ultra-violet lasers, which have a much smaller wavelength and can be used to read finer details.
If you haven't seen the advances then you haven't been looking. The recent sudden jump to hundreds of gigabytes on the cheap, for instance, is AFAIK the result of this IBM research. Yes, that article talks about 16.8 GB drives but that was just the first one available under that technology; I believe it is used in all high-capacity drives now.
There is no real marketing benefit to describing the real tech behind such devices, only assigning them buzzwords and hyping them up, so you only see stupid buzzwords.
The computer industry is actually very good about getting major advances in the hands of consumers on a time scale measured in months after the practical advances are made.
They are trying to make disks more reliable. Fluid dynamic bearings (FDB) don't wear out as easily as ball bearings. You know...that grinding sound that your disk makes as it spins up and searches for data...yeah that goes away with FDB.
:) Sure beat tapes at least.
I was just checking out a drive by western digital yesterday with FDB...a 160Gig unit. I think it was about a buck a gig, and I would assume much more reliable than my current lowly 30Gig and 20Gig drives...
ahhh...progress...
Hell, I remember being able to work on those REAL hard disk drives. You know, the cartridge ones. Roughly 15 inches in diameter...placed on a unit that stands up to your waist...with a reader arm as big around as my thumb that juts in and out like a pogostick....
Yeah, those were the days. Those drives are still usefull for the sake of basic electronics study though...makes it nice so that the students can see teh inner workings of a disk drive. I think they only stored like 8 Megabytes....maybe less.
Who is this that even the wind and the waves obey Him? Surely this computer must submit also!