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Using A Microscope As A Hard Drive
An unnamed correspondent writes: "Nature reports that IBM Zurich is
developing a practical method for
braille hard disks that may eventually be able to pack 60Gbits per square inch, or about four times current disk technologies. I wonder how many moving parts there are with 1024 read heads." Well, they're not really braille; perhaps the analogy to clay tablets made in the article is closer.
. . . you can still read your data (if your fingers are small enough).
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hello? anybody there? anybody read /.?"
Atomic force microscopy measures the force on a probe extremely near a surface. It measures electric interaction between the probe and the surface. Current hard drives probe the magnetic structure of the surface. As far as reading, it's nearly the same. The difference is in using an electrical probe rather than a magnetic one.
As for writing, I am curious about how rewritable it is.
I don't really have any idea how to go about answering your question, knowing nothing about the physics involved. Sorry. Perhaps you should have asked someone more informed.
I love making unfounded predictions based on technology I don't understand!
Please, optical is nice, but how many cd-drives have you worn out in the 3 years or so? I've got 3 of em chalked up, and I've yet to replace HD's...
Optical drives require moving parts as well - and these are just as likely to fail as reader heads on the basis of mechanics. The fact that there is 1024 heads is irrelevant! Have you ever taken statistics? Just because there are more of them doesn't atutomatically increase the rate at which they will fail, that is a property inherent in the device. Sure, if you have 1024 heads it is that much more likely that 1 of them will fail with respect to a system composed of 1 head but if the rate of failure of heads is less than 3 orders of magnitude than that of conventional mechanical devices then these heads would be less prone to mechanical failures.
By the way, In an atomic force microscope the reader heads don't actually come into contact with the source, that's the whole point! They only do so to write to the disc! - which I don't think implements the atomic force microscope aspect of the apparatus itself anyways.
Keep the whoring up, there's lots of jackass moderators that don't understand what you're talking about, and based on statistics they'll be more likely to support your unfounded skepticism than the 2 or 3% who actually understand what the hell this device is.
-An Anonymous Coward Against Unfounded Technical Criticism
> any idiot knows that a metal box shields what's inside what magnetic and radio interference by reflection...
Hah hah! Now explain why metal magnets aren't self-shielding.
Ryan
Personally, I've never had a CD or DVD drive fail, but that doesn't say that they don't fail. My point being: If my CD drive were to fail, I could just take out the media and it would be fine. With current hard drive technology, if one of the heads fails, and I have something I need on my drive (who here actually has current backups of ALL their files) I would be up shit creek. Using a laser as opposed to a mechanical head greatly reduces the chances of data loss due to drive failure.
Where exactly did you see that "the rate of failure of heads is less than 3 orders of magnitude than that of conventional mechanical devices"?
-atrowe: Card-carrying Mensa member. I have no toleranse for stupidity.
Actually I suspect it will be fine. At any visible scale, there will be just one head, flying over the disk in the normal way. At a microscopic scale, the head has a comb with 1024 tiny tines. Each tine is constantly adjusted to remain at a fixed height over the disk, by an individual feedback loop, and a piezo-electric actuator (a crystal that stretches or shrinks under electrical control). There are NO moving parts in the usual sense, just a few that stretch or bend. By reading off the activity in the feedback loop, and a fair bit of signal processing, the exact shape of the underlying surface can be read. In laboratory AFMs this is to literally atomic precision. I imagine the AFM disk would sacrifice a little of this for robustness.
Writing is accomplished by pushing the tine down a little further and scratching the (plastic) surface. Re-writing by heating a small area slightly with a laser so that it softens and surface tension flattens it.
Steve
I don't see why it should be especially over-sensitive. The pins would be suspended over a rotating disk, just as a magnetic head is now, and held at constant (small) altitude by a feedback loop and a piezo. The feedback loop is also the sensor. I imagine the feedback loop would be running at hundreds of KHz or even a few MHz, so most external shocks would be so slow that the signal processing software wouldn't even see them.
Basically, the heads are so small and working so fast, that external movement will no more disrupt them than a gently rocking ship disrupts your eye-tracking when you read a book.
The control and sensing electronics would be susceptible to interference just as a current magnetic devices are, but shielding is easy.
Writing is also safe enough. Think of using a pen on shipboard (not in a gale).
Steve
It's rewritable, although it might be like flash RAM, where you have to zero it in quite large chunks. To erase an area, you warm it with a laser until the surface flows, and surface tension flattens out all the little scratches which mark the bits.
As far as I know, you can do this as often as you like.
It isn't as slow as it sounds, because the areas involved, and the amounts and distances flowing are so tiny.
The Sumerians developed cuniform hard drives in 5000 B.C. Not only were these portable (literally fit in the palm of the hand), but they could be read very well from many different angles. There was one write head (known as a "stylus"). Since some of these drives are still readable, they also hold the world record as the oldest surviving portable data storage system.
The future lies in optical technology. The reason for this: Any drive in which the heads physically come in contact with the storage media is prone to failure. Standard magnetic hard drives fail often enough, but 1024 read heads is just insane. You'd be lucky to have the thing last a year. What we need to be working on is faster read/write speeds for optical media. Where are the 3D optical cubes I've been hearing about?
-atrowe: Card-carrying Mensa member. I have no toleranse for stupidity.
Not again! People have constantly been predicting that hard drives and processors would reach a limit in "a year or two", but has it ever happened? No!
In almost all situations, technologies do not just die but gradually evolve and lose the theoretical constraints that everyone was worried about. CDs have grown from storing 600 MB to 4 GB and soon 120 gigabytes.
And on a side note, doesn't this technology seem a lot like CD's? I'd much rather invest in the 120 GB multi-level CDs rather than this "microscopic Braille".
- BBoy doodles
C is for Cookie
It sounds, at this point, like the system will be somewhat fragile with so many heads and the notion of a third meaningful dimension in R/W. While at this point it seems too fragile for home use, clever shock-proofing and very good quality control in parts manufacturing could result in a reliable drive. In general, though, it's pretty cool. Unfortunately, the productization of this technology seems at least 5 years off, which means I'll have to stick with a pile of IBM 75GB drives for my (personal, sorry) MP3 server.
On a related note, has anyone else noticed that the claims of IBM's death were a bit premature? They seem to really have re-emerged as a major leader in R&D, and are piling up market leadership points in hard drives and Java tech while making inroads into monitors, back into PCs, and regaining ground lost to Sun, Intel, SGI, and DEC in the big-iron and supercomputing markets. Does anyone know of any really good insights into this in the form of articles, books, etc?
o/~ we are pissed, we are pissed, we have to resist... o/~ - ec8or
The article is available from the ACM in PDF format. A paid membership, or a small one-time fee, is required.
When a competing technology starts selling competitive devices (capacity, size, speed, reliability, etc.) at reasonable costs then I'll pay more attention.
On a side note, a little company called BiT Micro manufacturers high performance solid state storage devices in hard drive form factors, though at considerably higher cost.
Sure there needs to be research on what direction storage should head when we reach a limit on the capabilities of magnetic drives, but shouldn't we be focusing more on ways to improve the speed of the drives instead of the capacity?
This article states that although the new drives may hold many times more bits than today's drives, they will only run at about the same speed. Video editing is bad enough with the drives we have now. What is going to happen when we begin to work with HDTV streams or even uncompressed video?
This old scientific american article outlines serveral different techniques including the moziac.
Someone you trust is one of us.
"When it rains, it pours." --Morton's Salt
... 'cause the last thing I need is extremely dexterous blind people with sensitive fingers reading my email.
As a side note, where the hell does everybody park at the Special Olympics?
J
Well, the article doesn't mention anything about the rewritability of this type of device. From the description of this technology, it seems that it may be a write once type medium... or maybe limited to a few rewrites. But, it seems that the media would soon be incapable of holding futher writes. (Well, I guess one could erase it at a later date, but what would be the point?)
This would be useful, but only for backup type storage it seems... or a massive database where lots of data gets stored, but little change happens.
Anyone with any insight into this care to enlighten us as to whether this sort of technology could be used for massively rewritable storage?
File Servers
Large Databases
MP3 storage
Digital video editing
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There are quite a few applications where massive amounts of storage can outweigh the need for speed. If necessity mandates speed and massive storage, buy several Braille drives and set them up in a RAID 0 config.
-atrowe: Card-carrying Mensa member. I have no toleranse for stupidity.
sec... lost my train of thought.
ah, yes... and the time I used a pickled, held to an old Iron Butterfly album with a piece of duct tape, as a tape drive. And the only thing that kept that from working was that the pickle was just way too soggy. Perhaps I'll revisit this using a Valasic.
Hi! This is the Sig, blatantly attached to the end of this comment.