Researchers at MIT have designed a rechargeable lithium-ion battery that assembles itself out of microscopic materials. This could lead to ultrasmall power sources for sensors and micromachines the size of the head of a pin. It could also make it possible to pack battery materials in unused space inside electronic devices.
Yet-Ming Chiang, a professor of materials science at MIT, and his colleagues selected electrode and electrolyte materials that, when combined, organize themselves into the structure of a working battery. The researchers had been looking for ways to exploit short-range forces between micro- and nanoscale particles. After measuring such forces between materials using ultraprecise atomic-force microscope probes, they were able to select materials with just the right combination of attractive and repulsive forces. As a result, similar materials clustered together to form opposite electrodes, while a gap necessary for the battery to function was maintained between the electrodes. The work is the cover story in the current issue of Advanced Functional Materials.
Self-assembly is attractive because it could potentially reduce manufacturing costs and allow molecular-level control of the structure of the batteries, leading to materials and devices not easy to make using conventional manufacturing methods. Self-assembly has already been used to create a number of materials and a handful of simple devices, including half a battery. (See "Powerful Batteries That Assemble Themselves.") "Ultimately, the goal is just to chuck a bunch of stuff into a bucket and have it self-assemble into a battery," says Jeff Dahn, professor of chemistry and physics at Dalhousie University, in Canada. Chiang's work creating a prototype self-assembling battery is "really nice science," Dahn says. "Just the fact that you can do it is pretty cool."
The researchers faced a number of challenges in designing the self-assembling batteries. They are limited to materials with the electrochemical properties necessary for battery electrodes. And within each electrode, the particles need to pack together tightly, which can be accomplished if they are attracted to each other. The particles must also be attracted to materials that conduct electrons to and from the electrodes. Most important, the battery's two electrodes need to be kept separate--a challenge because they are oppositely charged and therefore tend to attract each other.
By relying on their new understanding of short-range forces, Chiang and his colleagues were able to select two electrode materials that, at very short distances on the order of a couple dozen nanometers, had surface repulsive forces greater than their attractive forces. As a result, there is always a space left between the electrodes.
The researchers used lithium cobalt oxide and microbeads of graphite for the electrodes--materials commonly used in lithium-ion batteries--pairing them with a carefully selected liquid electrolyte. The electrolyte serves as an insulator, allowing ions to shuttle between the electrodes but forcing electrons to move through an external circuit, where they can be used to power a device.
In the researchers' prototype battery, the graphite microbeads pack together to form one electrode and connect to a platinum current collector, all the while staying clear of the lithium cobalt oxide that forms the other electrode. The researchers tested the battery and showed that it could be both discharged and recharged multiple times.
The extent to which such batteries will find commercial applications is unclear. Dahn points out that in manufacturing today's batteries, the electrode materials are compressed under enormous pressures to ensure as great as possible energy storage. Such forces could not be applied to a self-assembled battery, so Dahn says it will be "very tough" to compete with conventional batteries in terms of energy capacity and maybe even in terms of cost. Dahn also notes that challenges still remain before such batteries can be commercialized. For example, it is still necessary to find a way to package the self-assembled materials to protect them once they have formed a battery.
One potential application is in very small devices. "It should be relatively easy to make a very small footprint device, rice-grain-size and smaller--the size of the head of a pin," Chiang says. He adds that self-assembly could allow more-efficient use of space than conventional batteries can. That's in part because it's possible for the electrode particles to pack into irregular shapes within a device or follow its outside contours.
As the researchers move toward such applications, which could include use in distributed sensors for the military, their next step is to replace the liquid electrolyte with a solid polymer to make the battery more rugged. The better understanding of the relevant short-range forces could also be used to select different materials for applications in transistors or certain types of solar cells.
Saturday, February 17, 2007
Friday, February 16, 2007
Countering Suicide Terrorism by RUSI (6th March 2007)
When detection is frustrated by scale and deterrence rendered near impossible by motivations, how can the state organise itself to defend against committed, would-be suicide attackers? The second session in the Homeland Security & Resilience Department’s series on suicide terrorism examines this issue of great import for all; not least the police and military personnel who carry the foremost burden in developing and applying policy.
The paramount near-term aim must be denial of tactical effect; saving lives, reducing perceptions of terrorist efficacy, sustaining public resilience and protecting valuable infrastructure. Improvements in intelligence, investigation, physical security and crisis management can together all contribute to the ultimate strategic defeat of terrorism.
This session will examine the ‘toolkit’ for countering suicide terrorism. Suicide attacks are not necessarily ‘sophisticated’, as often described. However, the will of the attackers and the absence of or relatively weak links to broader groups can make them difficult to detect and assess. This session outlines these issues, suggests possible solutions and opens the debate on an efficacious response that ensures public security and safety.
Speakers:
‘Intelligence & Counter Terrorism’ Sir Paul Lever KCMG Chairman, RUSI
‘Tactical Considerations for the Defeat of Suicide IEDs’ Major (retd) Chris Driver-Williams Counter IED Consultant, US DoD. Formerly, IED Intelligence Team Leader at the Defence Intelligence Staff, MOD
‘Protective Security: New Challenges’ Stephen Swain Security Consultant, Control Risks Group. Formerly, head of International Counter Terrorism Unit, Metropolitan police
‘Anti-Terrorism Investigations’ Detective Chief Inspector Chris Byrne SO15 Counter Terrorism Command, Metropolitan police
‘LTTE tactics and Government responses’ Dr. Brendan O’Duffy Senior Lecturer, Department of Politics, Queen Mary University of London
‘The Application of Non-Lethal Weapons in Anti-Terrorist Operations’ Dr. Tobias Feakin Head of Capabilties, Homeland Security & Resilience Department, RUSI
The paramount near-term aim must be denial of tactical effect; saving lives, reducing perceptions of terrorist efficacy, sustaining public resilience and protecting valuable infrastructure. Improvements in intelligence, investigation, physical security and crisis management can together all contribute to the ultimate strategic defeat of terrorism.
This session will examine the ‘toolkit’ for countering suicide terrorism. Suicide attacks are not necessarily ‘sophisticated’, as often described. However, the will of the attackers and the absence of or relatively weak links to broader groups can make them difficult to detect and assess. This session outlines these issues, suggests possible solutions and opens the debate on an efficacious response that ensures public security and safety.
Speakers:
‘Intelligence & Counter Terrorism’ Sir Paul Lever KCMG Chairman, RUSI
‘Tactical Considerations for the Defeat of Suicide IEDs’ Major (retd) Chris Driver-Williams Counter IED Consultant, US DoD. Formerly, IED Intelligence Team Leader at the Defence Intelligence Staff, MOD
‘Protective Security: New Challenges’ Stephen Swain Security Consultant, Control Risks Group. Formerly, head of International Counter Terrorism Unit, Metropolitan police
‘Anti-Terrorism Investigations’ Detective Chief Inspector Chris Byrne SO15 Counter Terrorism Command, Metropolitan police
‘LTTE tactics and Government responses’ Dr. Brendan O’Duffy Senior Lecturer, Department of Politics, Queen Mary University of London
‘The Application of Non-Lethal Weapons in Anti-Terrorist Operations’ Dr. Tobias Feakin Head of Capabilties, Homeland Security & Resilience Department, RUSI
Thursday, February 15, 2007
Cingular braves uncharted IMS waters by Kelly Hill
Cingular Wireless L.L.C. plans to deploy its Video Share product in the first half of this year, in what will constitute its first deployed IMS-supported application. The deployment of the Internet Protocol Multimedia Subsystem platform opens up new avenues for services and convergence for both the carrier and its newly merged parent, AT&T Inc.
Cingular demonstrated the technology at the Consumer Electronics Show in January. Video Share allows two users, who are both in high-speed HSDPA coverage areas, to initiate a live, one-way video feed while they are speaking to one another. The direction of the video feed can be reversed during the course of the call, and the device’s speakerphone automatically turns on so that the recipient of the call can see the screen and continue the conversation at the same time. Alcatel-Lucent Inc. supplied the IMS platform and the 3G network equipment for the demo, which utilized LG Electronics Co. Ltd.’s CU500v handset.
According to Kelly Williams, Cingular’s executive director of technology strategy, the recently deployed IMS platform will help Cingular and AT&T to be more nimble in application development and also open up new avenues for wireless/ wireline convergence.
In prior cases where Cingular needed to define a new signaling message element, Williams said, the process typically involved creating a standard and going through a standards process, then building and testing the actual application: a drawn-out progression that could take several years. IMS, he said, bypasses the necessity of the standards process.
“We can start creating services and going from ideation to market testing very, very quickly because we don’t have to do anything from a standards perspective,” Williams said. “It has the potential to make a huge difference in how quickly we can produce and roll out new products and services.”
What is IMS?
While Video Share is the first application, Williams said, it certainly won’t be the last. Before Cingular even began deploying IMS, he said, “We as a carrier had to define what it was and what we really wanted to use it for.”
IMS was just beginning to get traction when Cingular first became interested in creating a live video-sharing application, so the company began to scrutinize the architecture. Based on Cingular’s analysis of the platform, Williams said, the company concluded that IMS was “a legitimate architecture and something that was likely to be important.”
“IMS is an architecture and an enabler that allows for a rather elegant solution for wireless-wireline convergence,” Williams said. For instance, he said, it could allow an application to be used on a mobile phone, then seamlessly detect when a person enters their home and transfer the application to another device, such as a television or computer.
IMS allows different data “bearers” to access the application layer of the network, so applications could be used via multiple mediums without needing to be re-designed for each one, Williams said.
Europe, Asia leading IMS Deployments
Other carriers deploying IMS are mostly in Europe and Asia. Georges Smine, senior director of product marketing for Nominum Inc., said that operators around the world have gotten past the stage of learning about IMS and its capabilities.
“Now they’re trying to figure out, ‘How can we make money with this?’” he said. Nominum provides network naming and addressing solutions for IMS deployments.
He added that the IMS architecture has the potential to open up the networks to third-party developers and do for the world of telecom and telephony “what the software industry and the Internet did to the I.T. world” and take it from a mainframe-oriented world, where applications took a long time to develop, into a much more diffuse world, where applications can be developed by anyone with the right expertise.
Growth Expected, lead by Wireless
Research firm In-Stat has estimated that the number of subscribers to IMS-based services will grow from about 10 million in 2007 to more than 500 million by 2011. The company said that mobile operators would lead the way in establishing IMS-based networks and applications, driven by the desire to reduce operating costs as well as increase revenue.
Don’t Believe the Hype
Still, Cingular’s Williams acknowledged that there is an immense amount of hype surrounding IMS and its potential.
“We’re trying to see what the reality is, just like any carrier is,” he said. “We’re not buying into all the hype.” Instead, he said, Cingular is focused on “Does it really do what it says it’s going to do, what are the real applications and can we make some money at it?”
He said that IMS has the potential to allow the downloads of new services and applications without needing a new or specific wireless device.
Williams summed up Cingular and AT&T’s approach to IMS as a “middle path. We’re not evangelists for IMS, but we’re not saying that it’s meaningless, either.”
Key IMS Functional Elements
S-CSCF: The serving CSCF is the core of IMS. It identifies users’ service privileges and selects and provides access to the network application server. In addition, it maintains the session state while interacting with gateways, service platform elements and the charging function.
P-CSCF: The proxy-CSCF is the first point of contact within IMS for the subscriber that accepts requests and then either serves them internally or forwards them.
I-CSCF: The interrogating-CSCF finds the S-CSCF at registration and queries the HSS to retrieve a user’s location and routes the SIP request to its assigned S-CSCF.
HSS: The home subscriber server provides a central database that stores each subscriber’s unique service preferences and information (e.g., IM, voicemail)
MRFP: The multimedia resource function processor provides a source of media in the home network.
MRFC: The media resource function control is a signaling plane node that provides a media resource broker function between the app server and MRFP resource in the IMS.
MGW: The media gateway interfaces with the media plane of circuit switched networks.
Cingular demonstrated the technology at the Consumer Electronics Show in January. Video Share allows two users, who are both in high-speed HSDPA coverage areas, to initiate a live, one-way video feed while they are speaking to one another. The direction of the video feed can be reversed during the course of the call, and the device’s speakerphone automatically turns on so that the recipient of the call can see the screen and continue the conversation at the same time. Alcatel-Lucent Inc. supplied the IMS platform and the 3G network equipment for the demo, which utilized LG Electronics Co. Ltd.’s CU500v handset.
According to Kelly Williams, Cingular’s executive director of technology strategy, the recently deployed IMS platform will help Cingular and AT&T to be more nimble in application development and also open up new avenues for wireless/ wireline convergence.
In prior cases where Cingular needed to define a new signaling message element, Williams said, the process typically involved creating a standard and going through a standards process, then building and testing the actual application: a drawn-out progression that could take several years. IMS, he said, bypasses the necessity of the standards process.
“We can start creating services and going from ideation to market testing very, very quickly because we don’t have to do anything from a standards perspective,” Williams said. “It has the potential to make a huge difference in how quickly we can produce and roll out new products and services.”
What is IMS?
While Video Share is the first application, Williams said, it certainly won’t be the last. Before Cingular even began deploying IMS, he said, “We as a carrier had to define what it was and what we really wanted to use it for.”
IMS was just beginning to get traction when Cingular first became interested in creating a live video-sharing application, so the company began to scrutinize the architecture. Based on Cingular’s analysis of the platform, Williams said, the company concluded that IMS was “a legitimate architecture and something that was likely to be important.”
“IMS is an architecture and an enabler that allows for a rather elegant solution for wireless-wireline convergence,” Williams said. For instance, he said, it could allow an application to be used on a mobile phone, then seamlessly detect when a person enters their home and transfer the application to another device, such as a television or computer.
IMS allows different data “bearers” to access the application layer of the network, so applications could be used via multiple mediums without needing to be re-designed for each one, Williams said.
Europe, Asia leading IMS Deployments
Other carriers deploying IMS are mostly in Europe and Asia. Georges Smine, senior director of product marketing for Nominum Inc., said that operators around the world have gotten past the stage of learning about IMS and its capabilities.
“Now they’re trying to figure out, ‘How can we make money with this?’” he said. Nominum provides network naming and addressing solutions for IMS deployments.
He added that the IMS architecture has the potential to open up the networks to third-party developers and do for the world of telecom and telephony “what the software industry and the Internet did to the I.T. world” and take it from a mainframe-oriented world, where applications took a long time to develop, into a much more diffuse world, where applications can be developed by anyone with the right expertise.
Growth Expected, lead by Wireless
Research firm In-Stat has estimated that the number of subscribers to IMS-based services will grow from about 10 million in 2007 to more than 500 million by 2011. The company said that mobile operators would lead the way in establishing IMS-based networks and applications, driven by the desire to reduce operating costs as well as increase revenue.
Don’t Believe the Hype
Still, Cingular’s Williams acknowledged that there is an immense amount of hype surrounding IMS and its potential.
“We’re trying to see what the reality is, just like any carrier is,” he said. “We’re not buying into all the hype.” Instead, he said, Cingular is focused on “Does it really do what it says it’s going to do, what are the real applications and can we make some money at it?”
He said that IMS has the potential to allow the downloads of new services and applications without needing a new or specific wireless device.
Williams summed up Cingular and AT&T’s approach to IMS as a “middle path. We’re not evangelists for IMS, but we’re not saying that it’s meaningless, either.”
Key IMS Functional Elements
S-CSCF: The serving CSCF is the core of IMS. It identifies users’ service privileges and selects and provides access to the network application server. In addition, it maintains the session state while interacting with gateways, service platform elements and the charging function.
P-CSCF: The proxy-CSCF is the first point of contact within IMS for the subscriber that accepts requests and then either serves them internally or forwards them.
I-CSCF: The interrogating-CSCF finds the S-CSCF at registration and queries the HSS to retrieve a user’s location and routes the SIP request to its assigned S-CSCF.
HSS: The home subscriber server provides a central database that stores each subscriber’s unique service preferences and information (e.g., IM, voicemail)
MRFP: The multimedia resource function processor provides a source of media in the home network.
MRFC: The media resource function control is a signaling plane node that provides a media resource broker function between the app server and MRFP resource in the IMS.
MGW: The media gateway interfaces with the media plane of circuit switched networks.
Tuesday, February 13, 2007
Apple Hard At Work Making iPhone Obsolete by T.O.
Only a month after the much-heralded announcement of the iPhone, Apple CEO Steve Jobs confirmed that his engineers were already working around-the-clock on the touchscreen smartphone's far-superior replacement. "We looked at [the iPhone's] innovative user interface, the paradigm-shifting voicemail, the best-in-class mobile browser, and we realized we could make all that seem ridiculously outdated by the time the product becomes available to customers in June," said Jobs, who described the project as "Apple reinventing the iPhone." "When the second-generation iPhone comes out this fall, we want iPhone users to feel not just jealous, but downright foolish for owning such laughably primitive technology." Jobs also hinted that the second iPhone device would not be compatible with existing Mac computers, third-party peripherals, or any future Apple products.
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