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Flexible Sensors Make Robot Skin
Roland Piquepaille writes "In recent years, lots of efforts have been made to give robots the ability to hear and see. But what about the sense of touch? Unlike us, robots don't have sensitive skin. But this is about to change. By using organic, or plastic, field-effect transistors as pressure sensors deposited on a flexible material, researchers at the University of Tokyo have created an artificial skin which will give robots the sense of touch. The prototype has a density of 16 sensors per square centimeter, far from the 1,500 of our fingertips. When this density increases and when the problem of the reliability of this kind of transistors is solved, the researchers say this artificial skin will also be used for car seats or gym carpets. Expect to see them in four or five years. More details and a picture of a robotic hand using organic transistors as pressure sensors."
I haven't read the article yet, but my first thought when I read the blurb was whether or not this would have applications for prosthetics?
One of the most difficult parts of rehabilitation for amputees, even with the most expensive and advanced prosthesis, is that the most sensitivity available nowadays is a highly generalied "touching something/not touching something" or a translation of general amounts of pressure (and thats only on the most advanced: most models have no sensors at all). If we could provide amputees with limbs that felt, albeit in a much reduced fashion, many behaviors that require positive feedback (i.e. to be able to adjust your movements based on what you feel in that limb) could become accesible for the disabled.
"Stumble before you crawl"
"Look at yourself, standing there, cradling the new flesh I've given you. If it means nothing to you, why protect it?"
"I... I am simply imitating the behavior of humans."
"You're becoming more human all the time. . .Now you're learning how to lie."
"My programming was not designed to process these sensations."
"Then tear the skin from your limb as you would a defective circuit...Go ahead...! We won't stop you! Do it! Don't be tempted by flesh!"
The only acceptable defense of scientific results is to say that they were the product of the Scientific Method.
So they'll save lots of money on aftershave and electric razors.
All hail our new cleanshaven robot masters.
Everybody complaining about Slashdot becoming Piquepaille's personal soapbox for plagiarisim seems to get instantly modded down. Is he a pseudonym for one of the Slashdot editors or something?
Anyway, what is the robot ability up to now?
* Has skin
* Eats flies
* Can transform into other robots
* Walks on water
It sounds like the plans are coming together nicely for overlord robots.
As already mentioned, I see great things ahead for prosthetics. If this is a first shot at 16sensors/cm^2, surely it will be easy to make advances in not only materials but simple manufacturing processes that could greatly increase that.
It looks like the first in a long series of hurdles may just about be cleared.
There are also numerous industrial/scientific/sporting applications for something like this...imagine having NFL sidelines undercoated with this stuff...no more debate or bad vision angles....he was in or he was out. Or what about measuring even more precisely the impact at each discreet point on a runners feet? Or the force of a boxer's punch? Or the accuracy of a baseball bat or golf club as it comes into contact with the ball?
Cool stuff.
Haven't hered anything about it in the last 2-3 years, but Yeah, not new.
check out my blog, where i post comments interesting stuff related to robotics...
My post on this topic is here and below.
Flexible sensors make robot skin. This could have a number of applications. The first two I imagine are a richer interface between machines and humans and advanced manipulation.
If cheap enough, the machine can understand the precise location and posture of a human. Mentioned in the article are car seats. Imagine a bed which adjusted itself to minimize pressure points.
I should mention a project out of CMU by Chris Atkeson and Daniel Wilson, where he put only a few cheap accelerometers in the floorboard of a house. The algorithm processing these sensors could localize humans in the rooms with remarkable accuracy. The challenge then becomes sensor fusion and system integration, in using this information to boost performance of the entire system. For instance, a human tracker using vision alone would be dwarfed by such a system which had a reasonable seed guess from pressure sensors.
The second application is for rich manipulation. A robot grasping a glass must do so with enough pressure to not drop it, but also enough sensitivity to not break it. I doubt humans use significant higher reasoning in this process, unlike the advantage humans have over computer vision programs. Rather, robots could sense the weight fairly easily, but also the type of surface, and learn how brittle such a surface is.
Robo-Blogs of the world: UNITE!
I started a Masters degree on this issue in the 1980's and it's sad to see the same *wrong* approach to touch still being applied if the end use is a robotic hand/finger. At the time MIT was doing work on this, as were a few other places, all with the wrong approach. Here's the problem:
It's not the sensors or the density or how long they last or their accuracy or anything like that, even though these are real problems. The big killer problem is wiring. You get all these signals and at some point you need to get the wiring over joints that have to bend a real lot. And the more sensors you have the wires your typically going to have. Eventually you end up with bundles of wires and the simple fact is bundles of wires do not like being bent repeatedly, apart from which fingers need to be skinny to be useful and this is at odds with fat bundles of wires.
One solution however is physically simple and was presented at a National robotics conference in Australia in 1990. In summary I proposed and had made a working 2D slice of finger that used only 4 sensors. A 3D finger tip would require about 9 sensors, and by finger tip I mean measuring the major contact, magnitude and direction anywhere beyond the joint. The method was based on normal engineering and had the 4 sensors buried into a compliant skin. An external force caused a reading on all 4 strain gauges. From this small amount of data a PC worked out the magnitude, position and direction of the applied force using data collected from earlier testing. As a 2D finger slice it could successfully follow an edge when attached to a robot arm. I can scan and email the paper (this was pre net days) if any researchers want to extend this work and come up with practical robotic fingers. Email me.
Another solution is to put the smarts into the skin so only a "summary" signal needs to go back through the various joints. This couldn't be done in the 80's but could be now?
The tongue is the most sensitive body part (in multiple senses no less). Whether you consider that a risque part or not depends entirely on your predilections.
KFG
This is the same class of technology that Danny Hillis invented 25 years ago at the MIT AI Lab. At that time it wasn't organic transistors (just the plain 'ol inorganic kind) of course!
I can't find any specific references to it on the web, only some in passing. If I remember he used pantyhose to separate two conductive layers...
Most of the touch sensivity is provided by hair, not the skin itself. In fact, the skinn doesn't feel anything since it's made of dead cells. What gives us the perception of feeling are the nerves beneath the skin which connect to the small hairs outside. High detailed pressure and directional sensivity (used to feel textures) is provided by hair. The remaining touch feeling is the low detailed pressure one described in this article.
We have milions of small hairs all over the skin, even on the fingertips. Try placing two fingertips close to each other in front of your eyes and you will notice that you feel them touching before they actually touch each other, this is because of the small hairs there.
This is also the reason why people have hair on top of their heads, to protect them from accidentally colliding with stuff (and to keep the heat for that matter), my hair has helped me a lot avoidiong painful collisions with solid objects above me in the dark several times.
If you ever tried to shave to the point where there was no more hair on your face (pretty easy if you do it with a shaving blade), you've probably noticed that your touch sensivity decayed a lot for a while (until hair grown bck there later).
During research over the summer with tactile perception in humanoid robotics Ive come to believe that a type of flesh substance should be made. When mounting the sensors on a flat surface which would be the metal of the robot, non useful readings were shown with plots. After a few experiments with a 'skin' material we could see a considerable change in the readings, readings that possibly could be used to identify different structures.
In humans we note that our nerves are not mounted onto or bones but more suspended in flesh, this accounts for quite a bit of how we percieve cutaneous perception.