The flight of Chirarattananom’s RoboBee took place last summer but the research has only now been published. There’s a May 2, 2013 news release on EurekAlert heralding this robotic first from 2012,
In the very early hours of the morning, in a Harvard robotics laboratory last summer, an insect took flight. Half the size of a paperclip, weighing less than a tenth of a gram, it leapt a few inches, hovered for a moment on fragile, flapping wings, and then sped along a preset route through the air.
Like a proud parent watching a child take its first steps, graduate student Pakpong Chirarattananon immediately captured a video of the fledgling and emailed it to his adviser and colleagues at 3 a.m.—subject line, “Flight of the RoboBee.”
“I was so excited, I couldn’t sleep,” recalls Chirarattananon, co-lead author of a paper published this week in Science.
The demonstration of the first controlled flight of an insect-sized robot is the culmination of more than a decade’s work, led by researchers at the Harvard School of Engineering and Applied Sciences (SEAS) and the Wyss Institute for Biologically Inspired Engineering at Harvard.
Here’s what it looks like,
The tiny robot flaps its wings 120 times per second using piezoelectric actuators — strips of ceramic that expand and contract when an electric field is applied. Thin hinges of plastic embedded within the carbon fiber body frame serve as joints, and a delicately balanced control system commands the rotational motions in the flapping-wing robot, with each wing controlled independently in real-time. Credit: Kevin Ma and Pakpong Chirarattananon, Harvard University.
“We had to develop solutions from scratch, for everything,” explains Wood [Robert J. Wood, Charles River Professor of Engineering and Applied Sciences at SEAS, Wyss core faculty member, and principal investigator of the National Science Foundation-supported RoboBee project]. “We would get one component working, but when we moved onto the next, five new problems would arise. It was a moving target.”
Flight muscles, for instance, don’t come prepackaged for robots the size of a fingertip.
“Large robots can run on electromagnetic motors, but at this small scale you have to come up with an alternative, and there wasn’t one,” says co-lead author Kevin Y. Ma, a graduate student at SEAS.
The tiny robot flaps its wings with piezoelectric actuators — strips of ceramic that expand and contract when an electric field is applied. Thin hinges of plastic embedded within the carbon fiber body frame serve as joints, and a delicately balanced control system commands the rotational motions in the flapping-wing robot, with each wing controlled independently in real time.
At tiny scales, small changes in airflow can have an outsized effect on flight dynamics, and the control system has to react that much faster to remain stable.
While it’s called the RoboBee project, the researchers’ inspiration for this prototype is a fly. Unlike most flies, this one is tethered, at least for now (from Perry’s article),
The prototypes are still tethered by a very thin power cable because there are no off-the-shelf solutions for energy storage that are small enough to be mounted on the robot’s body. High-energy-density fuel cells must be developed before the RoboBees will be able to fly with much independence.
Future research plans include (from Perry’s article),
… integrating the parallel work of many different research teams that are working on the brain, the colony coordination behavior, the power source, and so on, until the robotic insects are fully autonomous and wireless.
Here’s a citation for and a link to the research paper,
On reading about the RoboBee project I was reminded of Michael Crichton’s 2002 cautionary tale, Prey, which focuses on a possible future where small, swarming bots that fly threaten to take over the world. More happily, I was also inspired musically and found this rendition of the Flight of the Bumblebee,
This Dec. 5, 2012 news item on Nanowerk features a seasonal approach to a study about ’4-D’ nanowires,
A new type of transistor shaped like a Christmas tree has arrived just in time for the holidays, but the prototype won’t be nestled under the tree along with the other gifts.
“It’s a preview of things to come in the semiconductor industry,” said Peide “Peter” Ye, a professor of electrical and computer engineering at Purdue University.
Researchers from Purdue and Harvard universities created the transistor, which is made from a material that could replace silicon within a decade. Each transistor contains three tiny nanowires made not of silicon, like conventional transistors, but from a material called indium-gallium-arsenide. The three nanowires are progressively smaller, yielding a tapered cross section resembling a Christmas tree.
Sadly, Purdue University (Indiana, US) will not be releasing any images to accompany their Dec. 4, 2012 news release (which originated the news item) about the ’4-D’ transistor until Saturday, Dec. 8, 2012. So here’s an image of a real Christmas tree from the National Christmas Tree Organization’s Common Tree Characteristics webpage,
Douglas Fir Christmas tree from http://www.realchristmastrees.org/dnn/AllAboutTrees/TreeCharacteristics.aspx
The Purdue University news release written by Emil Venere provides more detail about the work,
“A one-story house can hold so many people, but more floors, more people, and it’s the same thing with transistors,” Ye said. “Stacking them results in more current and much faster operation for high-speed computing. This adds a whole new dimension, so I call them 4-D.”
…
The work is led by Purdue doctoral student Jiangjiang Gu and Harvard postdoctoral researcher Xinwei Wang.
The newest generation of silicon computer chips, introduced this year, contain transistors having a vertical 3-D structure instead of a conventional flat design. However, because silicon has a limited “electron mobility” – how fast electrons flow – other materials will likely be needed soon to continue advancing transistors with this 3-D approach, Ye said.
Indium-gallium-arsenide is among several promising semiconductors being studied to replace silicon. Such semiconductors are called III-V materials because they combine elements from the third and fifth groups of the periodic table.
…
Transistors contain critical components called gates, which enable the devices to switch on and off and to direct the flow of electrical current. Smaller gates make faster operation possible. In today’s 3-D silicon transistors, the length of these gates is about 22 nanometers, or billionths of a meter.
The 3-D design is critical because gate lengths of 22 nanometers and smaller do not work well in a flat transistor architecture. Engineers are working to develop transistors that use even smaller gate lengths; 14 nanometers are expected by 2015, and 10 nanometers by 2018.
However, size reductions beyond 10 nanometers and additional performance improvements are likely not possible using silicon, meaning new materials will be needed to continue progress, Ye said.
Creating smaller transistors also will require finding a new type of insulating, or “dielectric” layer that allows the gate to switch off. As gate lengths shrink smaller than 14 nanometers, the dielectric used in conventional transistors fails to perform properly and is said to “leak” electrical charge when the transistor is turned off.
Nanowires in the new transistors are coated with a different type of composite insulator, a 4-nanometer-thick layer of lanthanum aluminate with an ultrathin, half-nanometer layer of aluminum oxide. The new ultrathin dielectric allowed researchers to create transistors made of indium-gallium- arsenide with 20-nanometer gates, which is a milestone, Ye said.
This work will be presented at the 2012 International Electron Devices (IEEE [Institute of Electrical and Electronics Engineers]) meeting in San Francisco, California, Dec. 10 – 12, 2012 (as per the information on the registration page) with the two papers written by the team will be published in the proceedings.
I have a full list of the authors, from the news release,
The authors of the research papers are Gu [Jiangjiang Gu]; Wang [Xinwei Wang]; Purdue doctoral student H. Wu; Purdue postdoctoral research associate J. Shao; Purdue doctoral student A. T. Neal; Michael J. Manfra, Purdue’s William F. and Patty J. Miller Associate Professor of Physics; Roy Gordon, Harvard’s Thomas D. Cabot Professor of Chemistry; and Ye [Peide "Peter" Ye].
According to the Nov. 7, 2012 news item on phys.org, the idea of powering batteries with vibrations from the inner ear is not new (Note: I have removed a link),
“In the past, people have thought that the space where the high potential is located is inaccessible for implantable devices, because potentially it’s very dangerous if you encroach on it,” Stankovic [Konstantina Stankovic, an otologic surgeon at MEEI {Massachusetts Eye and Ear Infirmary}]] says. “We have known for 60 years that this battery exists and that it’s really important for normal hearing, but nobody has attempted to use this battery to power useful electronics.”
Larry Hardesty’s Nov. 7, 2012 news release for the Massachusetts Institute of Technology (MIT), which originated the news item, provides more technical detail about how the researchers have reduced the risk associated with this type of implant,
In experiments, Konstantina Stankovic, an otologic surgeon at MEEI, and HST [Harvard-MIT Division of Health Sciences and Technology] graduate student Andrew Lysaght implanted electrodes in the biological batteries in guinea pigs’ ears. Attached to the electrodes were low-power electronic devices developed by MIT’s Microsystems Technology Laboratories (MTL). After the implantation, the guinea pigs responded normally to hearing tests, and the devices were able to wirelessly transmit data about the chemical conditions of the ear to an external receiver.
…
The ear converts a mechanical force — the vibration of the eardrum — into an electrochemical signal that can be processed by the brain; the biological battery is the source of that signal’s current. Located in the part of the ear called the cochlea, the battery chamber is divided by a membrane, some of whose cells are specialized to pump ions. An imbalance of potassium and sodium ions on opposite sides of the membrane, together with the particular arrangement of the pumps, creates an electrical voltage.
Although the voltage is the highest in the body (outside of individual cells, at least), it’s still very low. Moreover, in order not to disrupt hearing, a device powered by the biological battery can harvest only a small fraction of its power. Low-power chips, however, are precisely the area of expertise of Anantha Chandrakasan’s group at MTL.
The MTL researchers — Chandrakasan, who heads MIT’s Department of Electrical Engineering and Computer Science; his former graduate student Patrick Mercier, who’s now an assistant professor at the University of California at San Diego; and Saurav Bandyopadhyay, a graduate student in Chandrakasan’s group — equipped their chip with an ultralow-power radio transmitter: After all, an implantable medical monitor wouldn’t be much use if there were no way to retrieve its measurements.
But while the radio is much more efficient than those found in cellphones, it still couldn’t run directly on the biological battery. So the MTL chip also includes power-conversion circuitry — like that in the boxy converters at the ends of many electronic devices’ power cables — that gradually builds up charge in a capacitor. The voltage of the biological battery fluctuates, but it would take the control circuit somewhere between 40 seconds and four minutes to amass enough charge to power the radio. The frequency of the signal was thus itself an indication of the electrochemical properties of the inner ear.
To reduce its power consumption, the control circuit had to be drastically simplified, but like the radio, it still required a higher voltage than the biological battery could provide. Once the control circuit was up and running, it could drive itself; the problem was getting it up and running.
The MTL researchers solve that problem with a one-time burst of radio waves. “In the very beginning, we need to kick-start it,” Chandrakasan says. “Once we do that, we can be self-sustaining. The control runs off the output.”
Stankovic, who still maintains an affiliation with HST, and Lysaght implanted electrodes attached to the MTL chip on both sides of the membrane in the biological battery of each guinea pig’s ear. In the experiments, the chip itself remained outside the guinea pig’s body, but it’s small enough to nestle in the cavity of the middle ear.
The researchers seem to think that this kind of device might be used as a monitor for people with hearing difficulties or balance problems or, even, to deliver therapies. Regardless of any possible future uses, we are still a long way from human clinical trials.
For centuries it was thought that thin-film interference effects, such as those that cause oily pavements to reflect a rainbow of swirling colors, could not occur in opaque materials. Harvard physicists have now discovered that even very “lossy” thin films, if atomically thin, can be tailored to reflect a particular range of dramatic and vivid colors.
The discovery is the latest to emerge from the laboratory of Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS, whose research group most recently produced ultrathin flat lenses and needle light beams that skim the surface of metals. The common thread in Capasso’s recent work is the manipulation of light at the interface of materials that are engineered at the nano- scale, a field referred to as nanophotonics. Graduate student and lead author Mikhail A. Kats carried that theme into the realm of color.
“In my group, we frequently reexamine old phenomena, where you think everything’s already known,” Capasso says. “If you have perceptive eyes, as many of my students do, you can discover exciting things that have been overlooked. In this particular case there was almost a bias among engineers that if you’re using interference, the waves have to bounce many times, so the material had better be transparent. What Mikhail’s done—and it’s admittedly simple to calculate—is to show that if you use a light-absorbing film like germanium, much thinner than the wavelength of light, then you can still see large interference effects.”
The result is a structure made of only two elements, gold and germanium (or many other possible pairings), that shines in whatever color one chooses.
These are gold films colored with nanometer-thick layers of germanium. Credit: Photo courtesy of Mikhail Kats, Romain Blanchard, and Patrice Genevet
“We are all familiar with the phenomenon that you see when there’s a thin film of gasoline on the road on a wet day, and you see all these different colors,” explains Capasso.
Those colors appear because the crests and troughs in the light waves interfere with each other as they pass through the oil into the water below and reflect back up into the air. Some colors (wavelengths) get a boost in brightness (amplitude), while other colors are lost.
That’s essentially the same effect that Capasso and Kats are exploiting, with coauthors Romain Blanchard and Patrice Genevet. The absorbing germanium coating traps certain colors of light while flipping the phase of others so that the crests and troughs of the waves line up closely and reflect one pure, vivid color.
“Instead of trying to minimize optical losses, we use them as an integral part of the design of thin-film coatings,” notes Kats. “In our design, reflection and absorption cooperate to give the maximum effect.”
Most astonishingly, though, a difference of only a few atoms’ thickness across the coating is sufficient to produce the dramatic color shifts. The germanium film is applied through standard manufacturing techniques — lithography and physical vapor deposition, which the researchers compare to stenciling and spray-painting — so with only a minimal amount of material (a thickness between 5 and 20 nanometers), elaborate colored designs can easily be patterned onto any surface, large or small.
“Just by changing the thickness of that film by about 15 atoms, you can change the color,” says Capasso. “It’s remarkable.”
I will never look at another oily puddle the same way again.
The headline for the news item on Nanowerk and for the originating news release says ‘unforgeable’ but the researchers are being a little more cautious as I’m also seeing the words ‘almost impossible’ and ‘high probability’ in the text.
First, here’s a bit more about the researchers and their paper in an Oct. 2, 2012 news item on Nanowerk,
A team of physicists at Max-Planck-Institute of Quantum Optics (Garching [MPQ]), Harvard University (Cambridge, USA), and California Institute of Technology (Pasadena, USA) has demonstrated that such [noise-tolerant] protocols can be made tolerant to noise while ensuring rigorous security at the same time (“Unforgeable noise-tolerant quantum tokens”).
Whoever has paid a hotel bill by credit card knows about the pending danger: given away the numbers of the card, the bank account and so on, an adversary might be able to forge a duplicate, take all the money from the account and ruin the person. On the other hand, as first acknowledged by Stephen Wiesner in 1983, nature provides ways to prevent forging: it is, for example, impossible to clone quantum information which is stored on a qubit. So why not use these features for the safe verification of quantum money? While the digits printed on a credit card are quite robust to the usual wear and tear of normal use in a wallet, its quantum information counterparts are generally quite challenged by noise, decoherence and operational imperfections. Therefore it is necessary to lower the requirements on the authentication process. A team of physicists at Max-Planck-Institute of Quantum Optics (Garching), Harvard University (Cambridge, USA), and California Institute of Technology (Pasadena, USA) has demonstrated that such protocols can be made tolerant to noise while ensuring rigorous security at the same time (Proceedings of the National Academy of Science (PNAS), 18 September, 2012 [article behind a paywall]).
The researchers illustrated their news release with this image,
I have worked as a technical writer for telecommunications companies and in fact started with a data communications company that specialized in software for the financial services sector. Consequently, I feel reasonably comfortable about presenting this very brief overview of what happens when you (a legitimate user) put your credit/charge card or your bank/direct pay card (e.g. Interac) into a reader at a store or bank as a little background information before you read more about the ‘quantum credit card’.
All cards have bits of information on the magnetic strip which identify you and your financial institutions, e.g. your name, MasterCard, (issued by) Bank of Montreal
That data along with whatever amount you wish to charge or withdraw from your bank account is relayed from the reader through various pieces of hardware and software both to and from your financial institutions.
The hardware and software used in the transaction all operate according to protocols (rules for handling data). Difference pieces of hardware can and often do have different protocols as do the different pieces of software.
For example, if your cards and institutions are based in Mexico and you’re in India trying to charge a purchase, your data is being sent through the network set up by the various financial institutions (hardware and software) in India then eventually bounced to Mexico (it may not be direct) via satellite and sent through the networks in Mexico onto your institutions (hardware and software) and then back again. That’s a lot of hardware and software and while some of it may operate according to the same protocols, it’s reasonable to assume there’ will be a lot of changes and imperfections will creep in and this is the source of at least some of what the engineers call ‘noise’.
What I’ve just described (as accurately as I can recall) is the process for a legitimate user. These researchers are trying to find a means of foiling illegitimate users, which shifts the focus. Now, if I understand the information in the news release properly, the researchers have devised and tested two protocols for their unforgeable credit card (from the news release),
In both approaches, the bank issues a token and sends it to the holder. The “identity” of the token can be encoded on photons transmitted via an optical fibre or on nuclear spins in a solid memory transferred to the holder. However, only the bank stores a full classical description of these quantum states.
In the approach denoted by “quantum ticket”, the holder has to return the token to the bank or another trusted verifier for validation. The verifier is willing to tolerate a certain fraction of errors which should be enough to accommodate the imperfections associated with encoding, storage and decoding of individual quantum bits. The only information returned to the holder is whether the ticket has been accepted or rejected. Thus it is “consumed” and no longer available to the holder. The scientists show that through such an approach, both the likelihood of rejecting the token from an honest user and that of accepting a counterfeit can be made negligible.
The second approach is the “classical verification quantum ticket”. In some cases it may be impossible that the quantum tickets are given back to the bank physically. Here the holder has to validate his quantum token remotely – by answering challenge questions. The group considers a scheme where the quantum information is organized in blocks of qubit pairs. A non-revealing challenge question consists of requesting the holder to use a specific measurement basis for each block. By doing so, the holder is capable of providing a correct answer, but the token is consumed. This excludes the possibility for a dishonest user to cheat by answering complementary questions. As before, the given tolerance threshold determines the number of correct answers that is necessary for the verification of the token. The block structure used for the tokens allows exponentially suppressing the undesired capability of a dishonest holder to answer two complementary questions while assuring a true holder’s token will be authenticated with a very high probability.
For both protocols a realistic noise tolerance can be achieved. “We can deduce from theory that on average no more than 83% of the secret digits may be duplicated correctly by a counterfeiter. Under realistic conditions, we can assume that an honest participant should be able to recover 95% of the digits. If now the verifier sets the tolerance level to 90%, it will be almost impossible [emphasis mine] to accept fraudulent tokens or to reject an authentic holder,” Dr. Pastawski [Dr. Fernando Pastawski (MPQ)] explains.
I think they’re proposing two different approaches rather than the simultaneous use of two different protocols.
I’ve highlighted ‘almost impossible’ in the text of the news release as it is not the same thing as ‘impossible’ which is implied by the word ‘unforgeable’. It’s been my observation that whenever crime fighter types think they’ve devised a criminal-proof solution, criminals make a point of subverting the new technology. In any event, we’re a long way from seeing these ‘unforgeable’ credit cards, from the news release,
“I expect to live to see such applications become commercially available. However quantum memory technology still needs to mature for such protocols to become viable,” the scientist [Pastawski] adds.
A team from Harvard University have developed a technique for creating hydrogels that could be used effective in tissue engineering projects. From the Sept. 5, 2012 news release on EurekAlert,
A team of experts in mechanics, materials science, and tissue engineering at Harvard have created an extremely stretchy and tough gel that may pave the way to replacing damaged cartilage in human joints.
Called a hydrogel, because its main ingredient is water, the new material is a hybrid of two weak gels that combine to create something much stronger. Not only can this new gel stretch to 21 times its original length, but it is also exceptionally tough, self-healing, and biocompatible—a valuable collection of attributes that opens up new opportunities in medicine and tissue engineering.
Here’s an image of the hydrogel provided by the researchers,
The researchers pinned both ends of the new gel in clamps and stretched it to 21 times its initial length before it broke. Credit: Photo courtesy of Jeong-Yun Sun
“Conventional hydrogels are very weak and brittle — imagine a spoon breaking through jelly,” explains lead author Jeong-Yun Sun, a postdoctoral fellow at the Harvard School of Engineering and Applied Sciences (SEAS). “But because they are water-based and biocompatible, people would like to use them for some very challenging applications like artificial cartilage or spinal disks. For a gel to work in those settings, it has to be able to stretch and expand under compression and tension without breaking.”
To create the tough new hydrogel, they combined two common polymers. The primary component is polyacrylamide, known for its use in soft contact lenses and as the electrophoresis gel that separates DNA fragments in biology labs; the second component is alginate, a seaweed extract that is frequently used to thicken food.
Separately, these gels are both quite weak — alginate, for instance, can stretch to only 1.2 times its length before it breaks. Combined in an 8:1 ratio, however, the two polymers form a complex network of crosslinked chains that reinforce one another. The chemical structure of this network allows the molecules to pull apart very slightly over a large area instead of allowing the gel to crack.
The alginate portion of the gel consists of polymer chains that form weak ionic bonds with one another, capturing calcium ions (added to the water) in the process. When the gel is stretched, some of these bonds between chains break — or “unzip,” as the researchers put it — releasing the calcium. As a result, the gel expands slightly, but the polymer chains themselves remain intact. Meanwhile, the polyacrylamide chains form a grid-like structure that bonds covalently (very tightly) with the alginate chains.
Therefore, if the gel acquires a tiny crack as it stretches, the polyacrylamide grid helps to spread the pulling force over a large area, tugging on the alginate’s ionic bonds and unzipping them here and there. The research team showed that even with a huge crack, a critically large hole, the hybrid gel can still stretch to 17 times its initial length.
Importantly, the new hydrogel is capable of maintaining its elasticity and toughness over multiple stretches.
Anyone can see that the ability to stretch, self-heal and stretch mimics the body’s own processes and that materials which can mimic those processes are very promising. From the news item on ScienceDaily,
Beyond artificial cartilage, the researchers suggest that the new hydrogel could be used in soft robotics, optics, artificial muscle, as a tough protective covering for wounds, or “any other place where we need hydrogels of high stretchability and high toughness.”
If you’re interested, there are still more details in the news release on EurekAlert or in the news item on ScienceDaily.
A multi-institutional research team has developed a method for embedding networks of biocompatible nanoscale wires within engineered tissues. These networks—which mark the first time that electronics and tissue have been truly merged in 3D—allow direct tissue sensing and potentially stimulation, a potential boon for development of engineered tissues that incorporate capabilities for monitoring and stimulation, and of devices for screening new drugs.
The Aug. 27, 2012 news item on Nanowerk provides more detail about integration of the cells and electronics,
Until now, the only cellular platforms that incorporated electronic sensors consisted of flat layers of cells grown on planar metal electrodes or transistors. Those two-dimensional systems do not accurately replicate natural tissue, so the research team set out to design a 3-D scaffold that could monitor electrical activity, allowing them to see how cells inside the structure would respond to specific drugs.
The researchers built their new scaffold out of epoxy, a nontoxic material that can take on a porous, 3-D structure. Silicon nanowires embedded in the scaffold carry electrical signals to and from cells grown within the structure.
“The scaffold is not just a mechanical support for cells, it contains multiple sensors. We seed cells into the scaffold and eventually it becomes a 3-D engineered tissue,” Tian says [Bozhi Tian, a former postdoc at MIT {Massachusetts Institute of Technology} and Children’s Hospital and a lead author of the paper ].
The team chose silicon nanowires for electronic sensors because they are small, stable, can be safely implanted into living tissue and are more electrically sensitive than metal electrodes. The nanowires, which range in diameter from 30 to 80 nanometers (about 1,000 times smaller than a human hair), can detect voltages less than one-thousandth of a watt, which is the level of electricity that might be seen in a cell.
“The current methods we have for monitoring or interacting with living systems are limited,” said Lieber [Charles M. Lieber, the Mark Hyman, Jr. Professor of Chemistry at Harvard and one of the study's team leaders]. “We can use electrodes to measure activity in cells or tissue, but that damages them. With this technology, for the first time, we can work at the same scale as the unit of biological system without interrupting it. Ultimately, this is about merging tissue with electronics in a way that it becomes difficult to determine where the tissue ends and the electronics begin.”
The research addresses a concern that has long been associated with work on bioengineered tissue – how to create systems capable of sensing chemical or electrical changes in the tissue after it has been grown and implanted. The system might also represent a solution to researchers’ struggles in developing methods to directly stimulate engineered tissues and measure cellular reactions.
“In the body, the autonomic nervous system keeps track of pH, chemistry, oxygen and other factors, and triggers responses as needed,” Kohane [Daniel Kohane, a Harvard Medical School professor in the Department of Anesthesia at Children's Hospital Boston and a team leader] explained. “We need to be able to mimic the kind of intrinsic feedback loops the body has evolved in order to maintain fine control at the cellular and tissue level.”
Here’s a citation and a link to the paper (which is behind a paywall),
Macroporous nanowire nanoelectronic scaffolds for synthetic tissues by Bozhi Tian, Jia Lin, Tal Dvir, Lihua Jin, Jonathan H. Tsui, Quan Qing, Zhigang Suo, Robert Langer, Daniel S. Kohane, and Charles M. Lieber in Nature Materials (2012) doi:10.1038/nmat3404 Published onlin26 August 2012.
This is the image MIT included with its Aug 27, 2012 news release (which originated the news item on Nanowerk),
A 3-D reconstructed confocal fluorescence micrograph of a tissue scaffold. Image: Charles M. Lieber and Daniel S. Kohane.
At this point they’re discussing therapeutic possibilities but I expect that ‘enhancement’ is also being considered although not mentioned for public consumption.
Roomba, one of the better known consumer-class robots, is a hard-bodied robot used for vacuum-cleaning (or, hoovering as the Brits say). These days scientists are working on soft-bodied robots modeled on an octopus or a starfish or a squid. A team at Harvard University has added a camouflaging feature to its soft robot.
The Aug. 16, 2012 news release on EurekAlert provides some detail about the inspiration (in a field generally known as biomimicry or biomimetics),
A team of researchers led by George Whitesides, the Woodford L. and Ann A. Flowers University Professor [and well known within the field of nanotechnology], has already broken new engineering ground with the development of soft, silicone-based robots inspired by creatures like starfish and squid.
Now, they’re working to give those robots the ability to disguise themselves.
…
“When we began working on soft robots, we were inspired by soft organisms, including octopi and squid,” Morin said [Stephen Morin, a Post-Doctoral Fellow and first author for the paper]. “One of the fascinating characteristics of these animals is their ability to control their appearance, and that inspired us to take this idea further and explore dynamic coloration. I think the important thing we’ve shown in this paper is that even when using simple systems – in this case we have simple, open-ended micro-channels – you can achieve a great deal in terms of your ability to camouflage an object, or to display where an object is.”
“One of the most interesting questions in science is ‘Why do animals have the shape, and color, and capabilities that they do?’” said Whitesides. “Evolution might lead to a particular form, but why? One function of our work on robotics is to give us, and others interested in this kind of question, systems that we can use to test ideas. Here the question might be: ‘How does a small crawling organism most efficiently disguise (or advertise) itself in leaves?’ These robots are test-beds for ideas about form and color and movement.”
Peter Reuell’s Aug. 16, 2012 article for Harvard Science, which originated the news release, describes some of the technology and capabilities,
Just as with the soft robots, the “color layers” used in the camouflage start as molds created using 3-D printers. Silicone is then poured into the molds to create micro-channels, which are topped with another layer of silicone. The layers can be created as a separate sheet that sits atop the soft robots, or incorporated directly into their structure. Once created, researchers can pump colored liquids into the channels, causing the robot to mimic the colors and patterns of its environment.
The system’s camouflage capabilities aren’t limited to visible colors though.
By pumping heated or cooled liquids into the channels, researchers can camouflage the robots thermally (infrared color). Other tests described in the Science [journal] paper used fluorescent liquids that allowed the color layers to literally glow in the dark.
“There is an enormous amount of spectral control we can exert with this system,” Morin said. “We can design color layers with multiple channels, which can be activated independently. We’ve only begun to scratch the surface, I think, of what’s possible.”
The uses for the color-layer technology, however, don’t end at camouflage.
Just as animals use color change to communicate, Morin envisions robots using the system as a way to signal their position, both to other robots, and to the public. As an example, he cited the possible use of the soft machines during search and rescue operations following a disaster. In dimly lit conditions, he said, a robot that stands out from its surroundings (or even glows in the dark) could be useful in leading rescue crews trying to locate survivors.
So, if the scientists are pumping the colour into the soft robot, it’s still a long way from nature’s design where the creature produces its own colourants and controls its own camouflage in response to environmental factors.
Interestingly, there’s no mention of military applications for this camouflaging robot.
The Wyss Institute will receive up to $37M US for a project that integrates ten different organ-on-a-chip projects into one system. From the July 24, 2012 news release on EurekAlert,
With this new DARPA funding, Institute researchers and a multidisciplinary team of collaborators seek to build 10 different human organs-on-chips, to link them together to more closely mimic whole body physiology, and to engineer an automated instrument that will control fluid flow and cell viability while permitting real-time analysis of complex biochemical functions. As an accurate alternative to traditional animal testing models that often fail to predict human responses, this instrumented “human-on-a-chip” will be used to rapidly assess responses to new drug candidates, providing critical information on their safety and efficacy.
…
This unique platform could help ensure that safe and effective therapeutics are identified sooner, and ineffective or toxic ones are rejected early in the development process. As a result, the quality and quantity of new drugs moving successfully through the pipeline and into the clinic may be increased, regulatory decision-making could be better informed, and patient outcomes could be improved.
Jesse Goodman, FDA Chief Scientist and Deputy Commissioner for Science and Public Health, commented that the automated human-on-chip instrument being developed “has the potential to be a better model for determining human adverse responses. FDA looks forward to working with the Wyss Institute in its development of this model that may ultimately be used in therapeutic development.”
Wyss Founding Director, Donald Ingber, M.D., Ph.D., and Wyss Core Faculty member, Kevin Kit Parker, Ph.D., will co-lead this five-year project.
As for the Wyss Institute, here’s a description from the news release,
The Wyss Institute for Biologically Inspired Engineering at Harvard University (http://wyss.harvard.edu) uses Nature’s design principles to develop bioinspired materials and devices that will transform medicine and create a more sustainable world. Working as an alliance among Harvard’s Schools of Medicine, Engineering, and Arts & Sciences, and in partnership with Beth Israel Deaconess Medical Center, Boston Children’s Hospital, Brigham and Women’s Hospital, , Dana Farber Cancer Institute, Massachusetts General Hospital, the University of Massachusetts Medical School, Spaulding Rehabilitation Hospital, Tufts University, and Boston University, the Institute crosses disciplinary and institutional barriers to engage in high-risk research that leads to transformative technological breakthroughs. By emulating Nature’s principles for self-organizing and self-regulating, Wyss researchers are developing innovative new engineering solutions for healthcare, energy, architecture, robotics, and manufacturing. These technologies are translated into commercial products and therapies through collaborations with clinical investigators, corporate alliances, and new start-ups.
I hadn’t thought of an organ-on-a-chip as particularly bioinspired so I’ll have to think about that one for a while.
The ‘Medusoid’ is a reverse- tissue-engineered jellyfish designed by a collaborative team of researchers based, respectively, at the California Institute of Technology (Caltech) and Harvard University. From the July 22, 2012 news item on ScienceDaily,
When one observes a colorful jellyfish pulsating through the ocean, Greek mythology probably doesn’t immediately come to mind. But the animal once was known as the medusa, after the snake-haired mythological creature its tentacles resemble. The mythological Medusa’s gaze turned people into stone, and now, thanks to recent advances in bio-inspired engineering, a team led by researchers at the California Institute of Technology (Caltech) and Harvard University have flipped that fable on its head: turning a solid element—silicon—and muscle cells into a freely swimming “jellyfish.”
…
“A big goal of our study was to advance tissue engineering,” says Janna Nawroth, a doctoral student in biology at Caltech and lead author of the study. “In many ways, it is still a very qualitative art [emphasis mine], with people trying to copy a tissue or organ just based on what they think is important or what they see as the major components—without necessarily understanding if those components are relevant to the desired function or without analyzing first how different materials could be used.” Because a particular function—swimming, say—doesn’t necessarily emerge just from copying every single element of a swimming organism into a design, “our idea,” she says, “was that we would make jellyfish functions—swimming and creating feeding currents—as our target and then build a structure based on that information.”
Oops! I’m not sure why Nawroth uses the word ‘qualitative’ here. It’s certainly inappropriate given my understanding of the word. Here’s my rough definition, if anyone has anything better or can explain why Nawroth used ‘qualitative’ in that context, please do comment. I’m going to start by contrasting qualitative with quantitative, both of which I’m going to hugely oversimplify. Quantitative data offers numbers, e.g. 50,000 people committed suicide last year. Qualitative data helps offer insight into why. Researchers can obtain the quantitative data from police records, vital statistics, surveys, etc. where qualitative data is gathered from ‘story-oriented’ or highly detailed personal interviews. ( I would have used ‘hit or miss,’ ‘guesswork,’ or simply used the word art without qualifying it in this context.)
The originating July 22, 2012 news release from Caltech goes on to describe why jellyfish were selected and how the collaboration between Harvard and Caltech came about,
Jellyfish are believed to be the oldest multi-organ animals in the world, possibly existing on Earth for the past 500 million years. Because they use a muscle to pump their way through the water, their function—on a very basic level—is similar to that of a human heart, which makes the animal a good biological system to analyze for use in tissue engineering.
“It occurred to me in 2007 that we might have failed to understand the fundamental laws of muscular pumps,” says Kevin Kit Parker, Tarr Family Professor of Bioengineering and Applied Physics at Harvard and a coauthor of the study. “I started looking at marine organisms that pump to survive. Then I saw a jellyfish at the New England Aquarium, and I immediately noted both similarities and differences between how the jellyfish pumps and the human heart. The similarities help reveal what you need to do to design a bio-inspired pump.”
Parker contacted John Dabiri, professor of aeronautics and bioengineering at Caltech—and Nawroth’s advisor—and a partnership was born. Together, the two groups worked for years to understand the key factors that contribute to jellyfish propulsion, including the arrangement of their muscles, how their bodies contract and recoil, and how fluid-dynamic effects help or hinder their movements. Once these functions were well understood, the researchers began to design the artificial jellyfish.
To reverse engineer a medusa jellyfish, the investigators used analysis tools borrowed from the fields of law enforcement biometrics and crystallography to make maps of the alignment of subcellular protein networks within all of the muscle cells within the animal. They then conducted studies to understand the electrophysiological triggering of jellyfish propulsion and the biomechanics of the propulsive stroke itself.
Based on such understanding, it turned out that a sheet of cultured rat heart muscle tissue that would contract when electrically stimulated in a liquid environment was the perfect raw material to create an ersatz jellyfish. The team then incorporated a silicone polymer that fashions the body of the artificial creature into a thin membrane that resembles a small jellyfish, with eight arm-like appendages.
Using the same analysis tools, the investigators were able to quantitatively match the subcellular, cellular, and supracellular architecture of the jellyfish musculature with the rat heart muscle cells.
The artificial construct was placed in container of ocean-like salt water and shocked into swimming with synchronized muscle contractions that mimic those of real jellyfish. (In fact, the muscle cells started to contract a bit on their own even before the electrical current was applied.)
“I was surprised that with relatively few components—a silicone base and cells that we arranged—we were able to reproduce some pretty complex swimming and feeding behaviors that you see in biological jellyfish,” says Dabiri.
Their design strategy, they say, will be broadly applicable to the reverse engineering of muscular organs in humans.
For future research direction I’ve excerpted this from the Caltech news release,
The team’s next goal is to design a completely self-contained system that is able to sense and actuate on its own using internal signals, as human hearts do. Nawroth and Dabiri would also like for the Medusoid to be able to go out and gather food on its own. Then, researchers could think about systems that could live in the human body for years at a time without having to worry about batteries because the system would be able to fend for itself. For example, these systems could be the basis for a pacemaker made with biological elements.
“We’re reimagining how much we can do in terms of synthetic biology,” says Dabiri. “A lot of work these days is done to engineer molecules, but there is much less effort to engineer organisms. I think this is a good glimpse into the future of re-engineering entire organisms for the purposes of advancing biomedical technology. We may also be able to engineer applications where these biological systems give us the opportunity to do things more efficiently, with less energy usage.”
I think this excerpt from the Harvard news release provides some insight into at least some of the motivations behind this work,
In addition to advancing the field of tissue engineering, Parker adds that he took on the challenge of building a creature to challenge the traditional view of synthetic biology which is “focused on genetic manipulations of cells.” Instead of building just a cell, he sought to “build a beast.”
A little competitive, eh?
For anyone who’s interested in reading the research (which is behind a paywall), from the ScienceDaily news item,
Janna C Nawroth, Hyungsuk Lee, Adam W Feinberg, Crystal M Ripplinger, Megan L McCain, Anna Grosberg, John O Dabiri & Kevin Kit Parker. A tissue-engineered jellyfish with biomimetic propulsion. Nature Biotechnology, 22 July 2012 DOI: 10.1038/nbt.2269
Andrew Maynard weighs in on the matter with his July 22, 2012 posting titled, We took a rat apart and rebuilt it as a jellyfish, on the 2020Science blog (Note: I have removed links),
Sometimes you read a science article and it sends a tingle down your spine. That was my reaction this afternoon reading Ed Yong’s piece on a paper just published in Nature Biotechnology by Janna Nawroth, Kevin Kit Parker and colleagues.
The gist of the work is that Parker’s team have created a hybrid biological machine that “swims” like a jellyfish by growing rat heart muscle cells on a patterned sheet of polydimethylsiloxane. The researchers are using the technique to explore muscular pumps, but the result opens the door to new technologies built around biological-non biological hybrids.
Ed Yong’s July 22, 2012 article for Nature (as mentioned by Andrew) offers a wider perspective on the work than is immediately evident in either of the news releases (Note: I have removed a footnote),
Bioengineers have made an artificial jellyfish using silicone and muscle cells from a rat’s heart. The synthetic creature, dubbed a medusoid, looks like a flower with eight petals. When placed in an electric field, it pulses and swims exactly like its living counterpart.
“Morphologically, we’ve built a jellyfish. Functionally, we’ve built a jellyfish. Genetically, this thing is a rat,” says Kit Parker, a biophysicist at Harvard University in Cambridge, Massachusetts, who led the work. The project is described today in Nature Biotechnology.
….
“I think that this is terrific,” says Joseph Vacanti, a tissue engineer at Massachusetts General Hospital in Boston. “It is a powerful demonstration of engineering chimaeric systems of living and non-living components.”
Here’s a video from the researchers demonstrating the artificial jellyfish in action,
There’s a lot of material for contemplation but what I’m going to note here is the difference in the messaging. The news releases from the ‘universities’ are very focused on the medical application where the discussion in the science community revolves primarily around the synthetic biology/bioengineering elements. It seems to me that this strategy can lead to future problems with a population that is largely unprepared to deal with the notion of mixing and recombining genetic material or demonstrations of “of engineering chimaeric systems of living and non-living components.”
