Harvard Professor Creates Paper Accelerometer 87
SuperSlacker64 writes "In an age where just about everything starts going digital, it's refreshing to see someone going back to our roots: paper. Well, sort of. Researchers at Harvard have created a cheap, dime-sized, paper-based accelerometer that they believe could be used in various ways, such as inexpensive medical testing. The device works because a carbon bridge stretches and changes resistivity as the device is accelerated."
When they say "cheap," they mean it; the cost per device is estimated to be about four cents.
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Accuracy? (Score:2)
Re:Accuracy? (Score:5, Informative)
I hath sinned. I read the article. *hangs head in shame* The paper counterparts are far less sensitive. Silicon sensors give about 80 micronewtons while the paper give 120 un.
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But so what?
This wouldn't be used for precision instruments. It's be used for cheap laptops - get that drop protection that the high end ones have.
Children's bicycle helmets so that the over protective parents can have airbags installed in them.
Or any other situation where knowing the approximate acceleration or deceleration would be helpful.
Re:Accuracy? (Score:4, Informative)
It says for use in medical testing equipment where I'm pretty sure one would want precision, no?
Not every test, especially when aiming for low-cost, needs to reach Starfleet standards.
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not necessarily, for medical application you need accuracy, 120 un vs 80 un might be enough if the result are accurate. http://en.wikipedia.org/wiki/Accuracy_and_precision [wikipedia.org]
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Re:Accuracy? (Score:5, Insightful)
80 vs. 120 micronewtons isn't too bad. If by 'sensitivity' you mean the expected standard deviation for measurement noise, and assuming such noise is roughly gaussian, then you can almost achieve the precision of a silicon sensor by using two paper sensors and averaging the results (120/sqrt(2) = 84.9).
Throw together 25 of them (for a total cost of $1.00) and you can achieve 24 micronewton 1-sigma precision.
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80 vs. 120 micronewtons isn't too bad. If by 'sensitivity' you mean the expected standard deviation for measurement noise, and assuming such noise is roughly gaussian, then you can almost achieve the precision of a silicon sensor by using two paper sensors and averaging the results (120/sqrt(2) = 84.9).
Throw together 25 of them (for a total cost of $1.00) and you can achieve 24 micronewton 1-sigma precision.
Assuming the errors are independent.. which if the devices are identical they probably wouldn't be.
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It does matter, but not as much as the headline figures suggest. An accelerometer sensor (or any other sensor) needs wires to be installed to it, connections to be made (manually or as pads on a circuit board, whatever), a monitoring channel in an A-to-D (dedicated or multiplexed, it matters little), and calibration. Assigning a fixed and utt
Re:Accuracy? (Score:4, Insightful)
many applications require high-precision measurements, not just good approximations
And your point is...?
For any application that needs high-precision measurements, there are many others where lower precision would do fine, if only it wouldn't cost so much.
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No, no, no. We need one size fits all solutions. We can't have specialization! If this can't be put into my iPhone, or can't be used on commercial airliners, then what fucking use is it? Exactly. None.
The prosecution rests.
Sorry, that's a figure of speech, case closed!
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For high-precision measurements, there are expensive silicon accelerometers.
For everything else, there's AcceleCard...
Materials replace machines (Score:1)
I recall from a recent episode of David Pogue's TV show (NOVA, Making Stuff:Smaller), about things getting smaller (and cheaper), one of the themes was mechanical devices being replaced by materials. This looks like another example of that.
My world is topsy-turvy (Score:5, Insightful)
I thought professors were people who couldn't hack it in the real world, but it turns out academia is behind most innovation in one way or another? Color me retarded.
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>Whoever started the "professors are people who can't hack it" thing was not only wrong but being really vicious against some very competent, creative, and inventive people.
Or maybe he was just looking at the dregs who inhabit most college humanities departments.
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"Academics very often simply have a completely different view of money and status."
In my experience, this is not entirely true. Professors at my university all seek constant advancement (read: raises) and act as though they ascend to another class strata with their advancing salaries. Sure, they enter the process as open-minded PhDs begging for associate professorships, but boy do they gets egos quick!
I think the big difference between their kind and those in private R&D is that professors know that a u
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My partner works at the math department at our university. They're currently recruiting 2x faculty for tenure track. If you can get the grants, you can get tenure.
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As to the comment on whether or not they could hack it, well, I doubt they could in private industry (at least those I know well). They are just too needy and spoiled.
Unlike the godlike bankers who throw a hissy fit and swap jobs if they don't get their million dollar bonuses, the unutterable wankstains.
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No... the comparison is between research professors and private industry researchers. Bankers have nothing to do with it.
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A majority of academics are in the pursuit of knowledge and furthering their respective fields. When you are working for a company a majority of the time you are doing something that does not further the field of science and knowledge.
Agreed. Even if you *were* doing useful research, you likely would not be allowed to share it, ever. You have patents and copyright terms and by the end of them its not like companies just open up their records. They'd stay hidden forever. Patents give some insight but not all.
-Taylor
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Well, kind of. In the pursuit of profit, some times you do run across something remarkable. The problem is, much of the time the discovery is either held back as a trade secret, or patented. At least when it is patented, the public gets to see it, and eventually use it royalty free.
Same with the military. They have invented some neat stuff, all the in the pursuit of a better way to defend a country and/or kill other humans. The internet is the most obvious, but even Velcro® (hook and loop fasteners
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Academics have a track record for falsify documents the way programmers have a track record of liking Java.
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Re:My world is topsy-turvy (Score:5, Funny)
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Being outside of the Business world is pretty lucrative too. I was a temp for an agency that put me in many random jobs around MIT. When I had to do reception type work for professors, a lot of time was spent fielding calls from outside companies who needed a consultant.
One notable professor working in the Cancer Research center was away 90% of the time. It was full time work answering his phone and taking care of his office. I would get calls asking how much the hourly rate was for talking with this profe
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So this presumed world leader in his field earned as much as some shitty ambulance chasing lawyer? Gosh, how unfair of him.
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I never said it was unfair. I'm just contributing my experience. The "shitty ambulance lawyer" is disjoint from the conversation.
Anyway, my larger point is that they can still do quite well in the University setting. In fact, they get to refine their asset full time with research. Many of these professors, while not working directly for businesses, make a hefty amount of money as board members for those companies. At least in the tech field. It's no coincidence that a large number of Biotech and Pharmas
The world is right side up, don't worry. (Score:2)
I thought professors were people who couldn't hack it in the real world, but it turns out academia is behind most innovation in one way or another? Color me retarded.
Note that this is a Professor of Chemistry, and we're talking about physical sciences here.
Your sarcastic criticism refers to something still quite true for all the sophists in the 'Women's studies', 'philosophy', and similar departments.
In the physical sciences, bullsh*t is bullsh*t and often readily identifiable as such. In the 'softer' fields, there is no physical reality that must be lived up to. All one must do for such academic credentials is to spin reams of crap that tickles the egos of their predec
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And if you think there is a nice solid physical reality out there that is perfectly understood by tough-guy physical scientists you're also fucking deluded.
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I never claimed physical sciences are perfectly understood. I simply stated it's far easier to positively identify bullsh*t theories in the physical sciences than in the softer fields.
I'm sure a genuine student of philosophy- instead of some sophist jackass- would possess more refined logic, such that they wouldn't make the absurd jump between what I posted and what you responded with.
Now calm down, and go fetch me some fries. It's not my fault you're $100k in debt, the world doesn't recognize your 'genius'
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I thought professors were people who couldn't hack it in the real world, but it turns out academia is behind most innovation in one way or another? Color me retarded.
You fucking said it, pal.
from the trees-aren't-off-the-hook-yet dept. (Score:2)
cheap huh? (Score:1, Troll)
Re:cheap huh?What? (Score:2)
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Of course! (Score:5, Funny)
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I can see where this is going (Score:1)
Accelerometer embedded in paper. Now they can track every turn of a page -- to collect licensing perhaps?
Paper airplane with autopilot? (Score:2)
I wanna know what it would take to build a paper airplane with autopilot.
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Oh, come on, guys. (Score:2)
Missing parts... (Score:4, Informative)
Most accelerometers are not just a sense element.
The Analog devices ones from a few years back included an onboard reference (to allow single supply operation), and an on board buffer amplifier with externally settable gain (i.e. integrated op-amp). The 4 cent sensor still requires precision op-amps, nulling trim pots, etc to get a usable sensor. Don't forget packaging to protect the element from kinks, moisture, etc.
BUT, the most important thing about the accelerometers from Analog I used was they were laser trimmed for 0G, and used a very cool sense mechanism. The sensor was a micro-machined silicon mass on springs with a capacitive force/sense system that detects a perturbation of position by using a 1 MHz AC pump signal with a capacitive bridge and synchronous demodulation feedback. The mass is forced to be stationary by applying a DC electrical voltage on the capacitive sense plates, imparting a force 100% proportional to the applied DC voltage (i.e. purely LINEAR voltage to force relationship).
So what? Their system keeps the mass centered, thus making micro-machined springs that hold the mass irrelevant to the output voltage. In other words the NON-LINEARITY of crap springs is servoed out, and the output voltage is not an open loop measurement with gain, but a true measure of the force being applied to the tiny little mass by the acceleration trying to be measured.
Paper as a spring is not going to be repeatable from batch to batch, is subject to moisture, subject to fatigue, hysteresis, etc. Mad props for new uses of paper, but practical as a replacement for the devices it mocks it is not.
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The terms AC and DC have two subtly different meanings. In one of them, AC is distinguished from DC because AC oscillates and DC does not. In the other sense, AC differs from DC by virtue of the direction of current flow -- the current only "alternates" if it actually comes to a stop and flows in the opposite direction. It's possible to have oscillation without the current changing direction, for instance a 1 MHz oscillation that ranges from 0 volt to 1 volt. The current always moves in one direction, thoug
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(1 MHz AC) pump vs. 1 MHz (AC pump)
I should have said 1 MHz LO, and IF feedback instead of DC. I have trouble adjusting my terminology to more lay terms, sorry.
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[yada yada yada] ... but practical as a replacement for the devices it mocks it is not.
Um, yeah. Totally misses the point. It's not meant to replace those devices. It isn't even meant to replace the much cheaper, more widespread alternative to those devices (silicon MEMS sensors). From TFA:
Harvard chemistry professor and paper device pioneer George Whitesides, who led the new work, says he does not expect the paper sensors to replace silicon accelerometers. He doesn’t currently have specific applications in mind, but he expects the low-cost, lightweight, and easy-to-fabricate devices to open up new applications in different areas, from consumer gadgets to medicine.
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BUT, the most important thing about the accelerometers from Analog I used was they were laser trimmed for 0G, and used a very cool sense mechanism. The sensor was a micro-machined silicon mass on springs with a capacitive force/sense system that detects a perturbation of position by using a 1 MHz AC pump signal with a capacitive bridge and synchronous demodulation feedback.
I assume you then reverse the polarity and feed it back through the deflector dish?
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I was going to say the same thing...
Real World Billing (Score:1)
If it only costs four cents to manufacture, your doctor's office will bill $42.65 for it.
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If it only costs four cents to manufacture, your doctor's office will bill $42.65 for it.
Sure, they will do that because they know that insurance companies will take that bill and then only pay $.03 for it. They then need one uninsured person to agree to that increased price to make up for the money they lost to the insurance companies.
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Unless its on medicare and then they'll charge $420.65 for it.
Ahh, MEMS (Score:2)
undo (Score:3, Insightful)
Commenting to undo unintentional mod.
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1) Spend mod point
2) Reply to undo
3) Get modded up to receive more mod points than originally spent
4) ???
5) Profit!
Helps if you read (Score:2)
Z-axiz rotation (Score:1)
Why did I read that as (Score:1)
Way overhyped (Score:2)
Amazing new paper sensor!
Only 4c to manufacture!
The size of a dime!
120 micronewton accuracy!
Fine print:
Requires precision resistors for the wheatstone bridge, a high resolution ADC, and a microcontroller for minimal calibration. Also a temperature sensor and additional ADC for decent calibration. Sounds like about $3 worth of additional cost minimum.
A 10 second check of digikey shows you can get a *3-axis* MEMS accelerometer (MMA8453QT) in a 3x3x1mm package (MUCH smaller than a dime) for US$2 ($1.12 in 100
Not paper (Score:2)
It's not made of paper. It's made of paper, carbon and silver.
Inexpensive medical testing? (Score:1)
More importantly, precisely which medi