Proton-based transistor could let machines communicate with living things

Sep 20, 2011
On the right is a colored photo of the University of Washington device overlaid on a graphic of the other components. On the right is a magnified image of the chitosan fibers. The white scale bar is 200 nanometers. Credit: University of Washington

Human devices, from light bulbs to iPods, send information using electrons. Human bodies and all other living things, on the other hand, send signals and perform work using ions or protons.

Materials scientists at the University of Washington have built a novel transistor that uses protons, creating a key piece for devices that can communicate directly with living things. The study is published online this week in the interdisciplinary journal Nature Communications.

Devices that connect with the human body's processes are being explored for biological sensing or for prosthetics, but they typically communicate using , which are negatively charged , rather than protons, which are positively charged , or , which are atoms with positive or negative charge.

"So there's always this issue, a challenge, at the interface – how does an electronic signal translate into an ionic signal, or vice versa?" said lead author Marco Rolandi, a UW assistant professor of materials science and engineering. "We found a biomaterial that is very good at conducting protons, and allows the potential to with living systems."

In the body, protons activate "on" and "off" switches and are key players in biological energy transfer. Ions open and close channels in the cell membrane to pump things in and out of the cell. Animals including humans use ions to flex their muscles and transmit brain signals. A machine that was compatible with a living system in this way could, in the short term, monitor such processes. Someday it could generate proton currents to control certain functions directly.

A first step toward this type of control is a transistor that can send pulses of proton current. The prototype device is a field-effect transistor, a basic type of transistor that includes a gate, a drain and a source terminal for the current. The UW prototype is the first such device to use protons. It measures about 5 microns wide, roughly a twentieth the width of a human hair.

"In our device large bioinspired molecules can move protons, and a proton current can be switched on and off, in a way that's completely analogous to an electronic current in any other field effect transistor," Rolandi said.

The device uses a modified form of the compound chitosan originally extracted from squid pen, a structure that survives from when squids had shells. The material is compatible with living things, is easily manufactured, and can be recycled from crab shells and squid pen discarded by the food industry.

First author Chao Zhong, a UW postdoctoral researcher, and second author Yingxin Deng, a UW graduate student, discovered that this form of chitosan works remarkably well at moving protons. The chitosan absorbs water and forms many hydrogen bonds; are then able to hop from one hydrogen bond to the next.

Computer models of charge transport developed by co-authors M.P. Anantram, a UW professor of electrical engineering, and Anita Fadavi Roudsari at Canada's University of Waterloo, were a good match for the experimental results.

"So we now have a protonic parallel to electronic circuitry that we actually start to understand rather well," Rolandi said.

Applications in the next decade or so, Rolandi said, would likely be for direct sensing of cells in a laboratory. The current prototype has a silicon base and could not be used in a human body. Longer term, however, a biocompatible version could be implanted directly in living things to monitor, or even control, certain biological processes directly.

Explore further: Physicists consider implications of recent revelations about the universe's first light

Related Stories

Proton radiation more dangerous than once thought

Feb 20, 2006

At the NASA Space Radiation Laboratory at DOE's Brookhaven National Laboratory, scientists have found that proton radiation is more damaging to cells than previously assumed - specifically, the cells' DNA. ...

Hydrogen ions caught in the act of wandering

Oct 05, 2005

Erik T.J. Nibbering of the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI) and colleagues report for the first time experimental evidence of the motions of hydrogen ions (protons, H+) from acids ...

Recommended for you

Mapping the road to quantum gravity

6 hours ago

The road uniting quantum field theory and general relativity – the two great theories of modern physics – has been impassable for 80 years. Could a tool from condensed matter physics finally help map ...

Steering chemical reactions with laser pulses

14 hours ago

With ultra-short laser pulses, chemical reactions can be controlled at the Vienna University of Technology. Electrons have little mass and are therefore influenced by the laser, whereas the atomic nuclei ...

User comments : 26

Adjust slider to filter visible comments by rank

Display comments: newest first

Fionn
4.3 / 5 (7) Sep 20, 2011
Another step towards a glorious new future when every person will have the power to control and monitor their bodies' every function, from organ systems down to organelles and ion pumps. Just think of it: Your heart beating too fast from all that caffeine? Just think "slow to normal resting rate" and it's done! Allergic reaction? Tell your body to knock it off and it does!
ExcitedYetConcerned
5 / 5 (6) Sep 20, 2011
Yea, exciting and filled with potential, but considering the malleable nature of the brains programming I have my concerns.
*edit* I also can't help but think of the borg...
that_guy
2.8 / 5 (5) Sep 20, 2011
@Fionn. If you can just think your heart to slow to a normal resting rate after having too much caffeine, wouldn't you be able to do the opposite and have the caffeine effect without the caffeine in the first place?

For this transistor - Since you are losing ions, are they recovered, like in an electrical circuit? Does the transistor degrade over time through the loss of ions? I would imagine that moving Hy ions around would have a more complex affect on the chemistry around it than electrons. Is there anyone big in (bio)/chemistry that has some answers to this?
SincerelyTwo
4.2 / 5 (5) Sep 20, 2011
that_guy; increased heart rate is a side-effect, a consequences, of the drug and not the reason (most) people take it. It's affect in the mind, to increase alertness, is the desired effect. In other words, the 'good' comes with the 'bad,' and forcing the 'bad' effect doesn't give you alertness. You also can't create 'alertness' if the chemical doesn't exist.

You still need chemicals within you to mediate and support various effects, and to obtain energy.

Think about it this way, does opening and closing your front door cause amphetamine to manifest? Obviously not.

Consider that if you decreased your heart rate prematurely you could pass out or die from a stroke/etc, there is a very good reason why your body is trying to respond to being exhausted after a long run (for example). Too much control will lead to irresponsible decision making on the part of naivety.
Noumenon
4.7 / 5 (48) Sep 20, 2011
Another step towards a glorious new future when every person will have the power to control and monitor their bodies' every function, from organ systems down to organelles and ion pumps. Just think of it: Your heart beating too fast from all that caffeine? Just think "slow to normal resting rate" and it's done! Allergic reaction? Tell your body to knock it off and it does!


I think I'd rather trust the product of millions of years of human evolution, over the unintended consequences of naive reactionary button pushing.
Shootist
1 / 5 (1) Sep 20, 2011

I think I'd rather trust the product of millions of years of human evolution, over the unintended consequences of naive reactionary button pushing.


Anything designed by woman is the product of millions of years of evolution, all of which are unintended consequences.
Noumenon
4.9 / 5 (44) Sep 20, 2011
LOL
El_Nose
5 / 5 (4) Sep 20, 2011
the increase in heart rate from caffeine come from the fact that it is a vassal constrictor -- you are made more awake because it reduces blood flow -- the body over compensates for this by increasing heart rate higher than is needed but enough to insure blood to the brain is plentiful. -- go ahead and decrease that heart rate if you want to --

Personally i took this article on a totally different level than has been mentioned on this blog so far - a mind machine interface would be lovely - how would the brain handle additional sensory input?? Literally a new SENSE - a camera on your head that transmitted infrared light imagery to your brain, would we adapt or ignore the new sense organ? an amplifier for hearing.

but those are the easy ones to think of
-radiation detection
-magnetic field detection
-hazardous waste detection
-internet connection at all times
-never get lost
-control of an electronic tattoo by Phillips
-cell phone
-never needing to talk again
trekgeek1
5 / 5 (4) Sep 20, 2011
I don't think I'd trust myself to control my autonomous body functions. I fancy the idea of downloading information to my brain instead of learning it. Imagine a population where every individual can be an expert physicist, mathematician, and update daily news stories. An entire population well educated and informed and able to manifest their creativity through technology.
Otumeel
1.7 / 5 (3) Sep 21, 2011
No more idiots in third world countries. All transformed to the glorious sophistication of men and women of the first world.
Skultch
not rated yet Sep 21, 2011
This is a close step, no? My brain not worky good now. What can this do for brain scanning research? Could we add many parallel connections or a new type of processing ability to an individual brain to make it more powerful and self aware? Is it as simple as just setting up some connections and seeing what happens to the mice?
WorldJunkie
4 / 5 (1) Sep 21, 2011
We're moving closer to the state of full programmability. Now it's just the devices around us, which already has an unbelievably profound effect on our way of life. At some point it will be us. We will become some of those devices.
Everything programmable can be compromised programmatically. How about having a virus in your heart-regulating algorithm or in brain-concentration-aiding application? Or the Big Brother (or some petty hacker for that matter) listening to your thoughts remotely and recording them?
Not such a glorious future after all!
rsklyar
not rated yet Sep 22, 2011
Some similar and plagiaristic research at Northwestern University: issuu.com/r_sklyar/docs/sklyarvsmussaivaldi
Ricochet
5 / 5 (1) Sep 22, 2011
WE ARE HUMAN 2.0. YOU WILL BE DELETED.
Skultch
not rated yet Sep 22, 2011
WE ARE HUMAN 3.0 COMMENCE VERSION 1.1 UNDELETE....
El_Nose
5 / 5 (3) Sep 24, 2011
my MMI (mind machine interface) was installed on my 18th birthday as was normal ... Everyone remembers that day... the ride home in the car is silent, you parents sit you down in the living room and they give you their life -- in ten seconds you relive someone else's entire life-everything,every moment,feeling,experience. Its overwhelming. Then you do it with your other parent. The MMI interface has been around for 150 yrs. You get to see when your grandparents did it to them. you live through that as well since your parents also experienced it. and on down the line. both my parents alive and all subsequent parents as well. I saw 64 peoples entire life from their point of view. And another 180 people from the lives that had been shared with them. Appearently its customary to share yourself with your best friend first, I know that not because anyone told me - but i have already experienced it a few hundred times. and its wonderful. and my grandma was an physicist - s!*t i know physics
El_Nose
5 / 5 (3) Sep 24, 2011
-MMI (college ) --

since the mind machine interface went live 500yr ago education has taken a whole new route. Instead of quaintly going to college as was customary in the 20th and 21st centuries one know buys their educational experience - for $500k one can live through college life 5000 times over in just under an hour. How well would you know advanced string theory if you heard it no less than 500 times through 500 different perspectives... and the highly motivated lives of those people. MIT know offers a musically gifted physics degree, you will know the works of every Ph.d that the school has ever collaborated with, and every Julliard graduate. And just to better round you out you get 100 party 'ers from the best business schools to complete your education. no less than 1.9M Ph.d's in science major 3.8M Ph.d's in the arts. 50M Engineers and 4 Presidents. All for 10M. Or 30% of your salray for the next 10 yrs plus mind access.

MIT - where our motto is "gone but not forgotten"
Skultch
5 / 5 (2) Sep 25, 2011
my MMI allowed my wife and I to essentially become one person; one consciousness, yet still two individuals, at the same time. With selective entanglement, every new experience is shared simultaneously, but only when the feature is "on." We still have our individual biology and emotional intelligence as differences, so even our common experiences are perceived differently, which is may or may not be shared.
El_Nose
not rated yet Sep 26, 2011
yeaaa skultch .... i was trying to get people to think through inventions and issues -- nicely done sir
Skultch
5 / 5 (1) Sep 26, 2011
Thanks. Yeah. My post was specifically aimed at the "we will become The Borg" fears. It's good that we have already theoretically explored the inhumanity that can bring. Now we can avoid it. So many people are caught up in the risks and deem them too high to even continue discovery. I think that's the wrong approach. There's no end in sight to our ability to understand then utilize knowledge. Evolution, for example, is an unguided process that is far from ideal. We just have more work to do, that's all.
Ricochet
5 / 5 (1) Sep 26, 2011
With my MMI, I experience the lives of random people on the street. They head into my darkened section, where they are subdued. I make the link, then start the transfer just as they regain consciousness.
Immediately, I can feel them, feel everyone they've interfaced with. I know their fears, their worries, their loves. I feel all the lovers they've had. That's my favorite part. Of course, they also feel me, and everyone I've interfaced with. They may know their friends and neighbors now like they've never known before. They feel everything I have felt, and everyone I've interfaced with.
Soon, I will know everyone. I am the human condition. You could call it rape, but no one ever talks about me. No one. They don't have to. They all know me.
that_guy
not rated yet Sep 26, 2011
that_guy; ... Too much control will lead to irresponsible decision making on the part of naivety.


JEEBUS PEOPLE. All I was saying was that to the first comment, was that if you could counteract the effect of caffeine with this technology, you would be able to mimic the effect of caffeine with it in the first place, thus negating the motivation to take caffeine in the first place.

Sheesh.
Ricochet
not rated yet Sep 26, 2011
that_guy; ... Too much control will lead to irresponsible decision making on the part of naivety.


JEEBUS PEOPLE. All I was saying was that to the first comment, was that if you could counteract the effect of caffeine with this technology, you would be able to mimic the effect of caffeine with it in the first place, thus negating the motivation to take caffeine in the first place.

Sheesh.


We wouldn't be consciensous webizens if we didn't point out things like that... it's one of those things that they'd have to prevent anyone from changing things beyond safety limits.
Skultch
5 / 5 (1) Sep 26, 2011
with my MMI, I have begun seeking out MMI "rapists" and selecting them for removal from the cloud. It's my job.
Leannemo
5 / 5 (1) Sep 28, 2011
With an impending MMI installation, I am training with an assimilation interface called Facebook. I already have begun to slowly acclimate to a constant stream of other people's thoughts, actions, histories, applications, et cetera...and many have begun to accept mine. Although my knowledge base has increased slightly, the data cannot compete to that which my MMI will upload. My birthday can't get here fast enough! LOL IMH (in my head). :)
Ricochet
not rated yet Sep 28, 2011
Maybe it'd be Mindbook at that point?

More news stories