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computing

News

N

anotechnology helps make the per-

vasive aspect of pervasive comput-

ing possible. One obstacle to putting

computers everywhere is size. You can

put a desktop computer, well, on your

desktop. But you can’t put it in your

bloodstream (such pervasive computing

applications are indeed being explored).

Shrinking computers makes it possible

to put them almost anywhere.

To envision nanotechnology’s poten-

tial, think about building things from the

molecular level up. At that level, you can

build in characteristics and capabilities

that aren’t readily apparent. Fueled by

numerous drivers (see the sidebar), proj-

ects from data storage to power genera-

tion to medical exploration are all put-

ting nanotechnology to use.

In IBM’s Zurich Research Lab, sci-

entists are engineering a new data-stor-

age technology called Millipede. Instead

of a thousand legs, this Millipede has

thousands of silicon tips, each with an

apex of about 10 nanometers (nm),

many times thinner than a human hair.

These tips serve as read-write heads for

recording and retrieving data inside the

Millipede storage device.

The tips store data by punching holes

into an extremely thin plastic film. The

tips are heated and a small force is

applied to make indentations of about

10 to 20 nm. The tips can read and

erase data as well. “This fits into a tiny

form factor with data densities on the

order of one to three terabits per square

inch,” says Peter Vettiger, who initiated

the project with Nobel Laureate Gerd

Binnig. That’s many, many times more

memory than the smallest storage that

devices have today.

Millipede’s envisioned form is about

the size of a secure digital card—a mem-

ory card the size of a postage stamp

weighing less than an ounce—and it

will have the storage capacity of dozens

of gigabytes. “It is a considerable

improvement in terms of capacity,” says

Vettiger.

Its initial application will be in con-

sumer electronics as a high-end flash

memory technology, such as for mobile

applicationsincameras,camcorders,lap-

tops, mobile phones, and MP3 players.

“You will have your entire library of

music with you in your MP3 player,”

says Vettiger. You will be able to down-

load, store, and play movies on your

cell phone and store, all the pictures you

ever take on your camera.

These memory specs are ideal for con-

sumer electronics but could eventually

extend to areas such as data archives or

everyday data storage, says Vettiger. The

storage cards might appear in consumer

electronics around 2009.

The silicon tip research has culmi-

nated in a working laboratory proto-

type that demonstrates many features

necessary in commercial products, but

further research is required and under

way. Mobile devices are subject to sud-

den shock and vibration and adverse

temperatures. Stored data must remain

stable over time despite these challenges.

The silicon tips also must retain their

sharpness for at least 10 years to read

and write data for a reasonable prod-

uct life. “These are the kinds of things

the Millipede team is working on,” says

Vettiger. “We are quite confident that

we will be able to meet all of these

requirements.”

InOctober2005,Singapore’sNanyang

Technological University announced

the development of one of the world’s

tiniest transformers for electronic

gadgets. According to the university,

at only five times the thickness of a

human hair, the transformer is one-

Features Editor: Chandra Narayanaswami

News

I Nanotechnology: The

I Robo-Teddy: Today’s

computing

third the size of other transformers

developed thus far.

“We are excited about the possibili-

ties for this technology in the design and

production of a multitude of consumer

electronics,” says Yeo Kiat Seng, head

of the division of circuits and systems

in NTU’s School of Electrical and Elec-

tronic Engineering.

The NTU transformer is built into the

integratedcircuit(IC)—amicrochipwafer

or a consumer electronics computer

chip—whereas traditional transformers

are a separate component. According to

Ng Aik Kiat of NTU corporate commu-

nications, this lets manufacturers save

space and production costs, which trans-

lates into smaller, cheaper consumer elec-

tronics such as mobile phones, radios,

TVs, and computers.

NTU is seeking partners to bring the

transformer, three years in the making,

to production. “Our next step is to

bring it from the lab to the streets,

where consumers can realize its bene-

fits,” says Yeo. NTU researchers hope

to follow this breakthrough by incor-

porating entire systems of electrical and

electronic components into ICs.

Shrinking gadgets plus added func-

tionality equals a growing demand for

longer-lasting, nanosized power sources.

“A lot of cadmium batteries now have

carbon nanotubes as electrodes,” says

Vinayak Dravid, a professor in the

department of materials science and

engineering at Northwestern University.

A nanotube is a long, round carbon

structure made of graphite molecules.

Nanotube electrodes improve the

energy density in these batteries, afford-

ing longer battery life.

Nanotechnology is springing up in

nontraditional power storage, as well.

Konarka’s Power Plastic is an example

of a solar-power storage material, also

referred to as plastic solar, says Daniel

McGahn, the solar-materials devel-

oper’s executive vice president. Plastic

solar offers several advantages over sil-

icon solar cells.

According to McGahn, plastic solar

is made of conducting polymers (yes,

some plastics do conduct electricity) and

nano-engineered materials that can be

used to coat surfaces. Konarka’s plastic

solar material provides DC current that

I

t’sasuresignthatpervasivecomputing

has entered a new era—in some ways

even more telling than the PC’s domi-

nanceorwirelesscommunication’semer-

gence.Thegoodold-fashionedteddybear

has become an intelligent agent.

Computer scientists are now using

stuffed toys as intelligent agents in an

array of applications—from bunnies

and squirrels that serve as cell phone

answering devices to bears that func-

tion as “living” log recording devices.

What’s the significance of equipping

stuffed toys with emerging technolog-

ical capabilities? And how could this

type of research affect computing on a

larger scale?

Call it the cute factor. According

to Stefan J.W. Marti, HCI researcher

at MIT Media Laboratory, people

react positively to embodied agents,

such as stuffed toys, mainly on an

emotional level. “Although those

reactions are often unconscious, they

are statistically highly significant,”

he says.

Marti has developed a computerized

stuffed squirrel that fields cell phone

calls, takes messages, and alerts its

owner through movement to important

calls or new voicemail (see http://web.

#current). It’s wireless and mobile. He

says he chose the squirrel in part

because of its cuteness; there’s also a

rabbit model.

Marti has received numerous sug-

gestions for embodiments, including

traditional-looking robots as well as

characters such as Darth Vader and

The Terminator.

“They all are possible options since

my work is only assuming that the

embodiment is afforded with the abil-

ity to express itself with nonverbal

cues, which is possible in many ways,”

he says. “People have different pref-

erences as to how lifelike, fluffy, or

realistic the embodiment should ide-

ally be.”

Marti says that cultural attitudes

have also influenced his approach.

“We noticed that people from Asian

in brief...

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devices can store, use immediately, or

convert to other forms of energy.

“Because Konarka’s technology uti-

lizes a wider range of the light spectrum

than conventional solar cells, all visible

light sources—not just sunlight—can be

used to generate power,” says McGahn.

Power Plastic makes it possible to

seamlessly build battery-power regen-

eration into any powered product that

will be exposed to some kind of light.

“Solar no longer needs to be a separate

aftermarket system constrained by

weight, size, rigidity, or installation

concerns,” says McGahn.

You can find Power Plastic in sup-

plies and equipment provided to the US

Army and the US Air Force. These

include small, mobile AA battery charg-

ers for use with soldiers’ handheld

NEWS

JANUARY–MARCH 2006

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cultures, especially Tokyo and Seoul,

have a much more relaxed perception

of robots and animatronics than West-

ern cultures.”

Kenji Mase, professor of information

architecture and technology at Nagoya

University, is using a teddy bear—what

he refers to as a “stuffed toy inter-

face”—in his research into computer-

mediated communication. The bear has

dual functionality as a log recording

device and a daily partner.

Explains Mase, “The log is used as a

review of what the toy watched and lis-

tened to as well as to augment review

of [the bear’s] tactile interactions with

humans, such as holding and petting.”

Mase says the bear’s intimate inter-

facing functionality, part of its role as

daily partner, will be a necessary fea-

ture of future robots, whatever the

robot’s target tasks.

Cynthia Breazeal, associate professor

of media arts and sciences at MIT, is

developing the Huggable—a therapeu-

tic interactive bear for hospitalized chil-

dren. The bear could also be used to

assist children exposed to traumatic sit-

uations, such as Hurricane Katrina.

Breazeal and her colleagues were

inspired by animal-assisted therapy and

affective touch interactions’ health ben-

efits for hospital patients (see http://

robotic.media.mit.edu). The scientists

believe the Huggable could augment

such programs.

“Living animals can only visit for a

limited period of time,” explains

Breazeal. “The Huggable would allow

us to understand if longer-term inter-

action provides additional or different

benefits to hospitalized children.

“Also, given that the Huggable is in

reality a sophisticated robot with sig-

nificant computational power, we’re

discussing with [health professionals]

how the Huggable might play a role in

helping hospital staff with their job,

such as monitoring patient activity.”

According to Breazeal, children’s vis-

ceral reaction to the bear is a funda-

mental part of the study. “It cannot

sound like a machine with noisy motors

and gearboxes. We want it to feel as

much as possible like holding an

organic creature,” she says.

If nothing else, research using stuffed

toys might signal what the future holds

for ubiquitous computing and anima-

tronics. Marti predicts that sensor

nodes and microcontrollers will

increasingly be built into everyday

objects, including clothes, jewelry, and,

of course, stuffed toys.

“Everyday objects will become

technologically more complex so that

an abstraction layer may be necessary

in addition to the actual computa-

tion,” he says. “This layer may well

be autonomous and proactive agent

technology.”

M

ase believes that emerging tech-

nologies will allow computa-

tional communication in the future to

move from merely transmitting factual

information to recording and sharing

everyday experiences, exchanges, and

emotions.

devices, tents that draw power from

light outdoors to power equipment

indoors, and self-powered sensor sys-

tems in which the housing is made of

Power Plastic.

Potential consumer products that

parallel military applications include

battery chargers for cell phones, MP3

players, cameras, and PDAs. The next

step is making casings out of Power

Plastic for the devices themselves, says

McGahn.

Security and environmental sensors,

lighting systems, and camping and

recreational gear are all feasible com-

mercial applications of plastic solar. In

three to five years, Konarka expects to

see its solar plastic in roofing materials,

awnings, and window treatments, says

McGahn. In this decade, he adds, the

company sees plastic solar in textiles

woven from photovoltaic fibers. Pho-

tovoltaic fibers would be capable of

turning light into direct current.

According to McGahn, plastic solar

will have its greatest initial impact on

portable electronics, sensor networks,

and architecture. Plastic solar can sup-

port electronics with more functions for

longer periods regardless of form fac-

tor. Sensor networks will span larger

areas, detect and transmit more infor-

mation, and work efficiently with fewer

maintenance issues because of fewer

power constraints. Architecture will be

seamlessly imbued with the ability to

generate power. You can make solar

low cost and make it blend in visually,

says McGahn.

Most of Power Plastic’s obstacles are

in the marketplace, says McGahn, but

it’s edging its way in, one niche appli-

cation at a time.

NASA Ames Research Center’s short-

term nanotechnology efforts focus on

chemical and biosensors using carbon

nanotubes, says Meyya Meyyappan,

director of the NASA Ames Center for

Nanotechnology. “The chemical sen-

sors are used to look for gases and

vapors like carbon dioxide, methane,

NO

2

(nitrogen dioxide),” says Meyyap-

pan, not only on other planets but also

on Earth.

The biosensors are applicable to

water-quality monitoring in human

environments such as space stations

and exploration vehicles, says Meyyap-

pan. Both of these examples have

potential threat-detection applications

in homeland security, he adds. Advan-

tages in addition to the sensors’ tiny

mass include greatly heightened sensi-

tivity to gases and biological triggers

over currently available equipment.

Very small sensors are crucial in

aerospace because of the rising cost

per pound of sending up material.

“For Mars and beyond, it will cost

US$100,000 per pound,” says Meyyap-

pan. To reduce launch costs, NASA is

also reducing to nanoscale instrumen-

tation and any other applicable items.

Making an individual sensor is com-

paratively easy when you consider the

supporting technologies you must build

around sensors to make them of any use.

“The sensor gives you a signal when a

gas or vapor gets on to the conductive

channel of the sensor, but the sensor is

only one component,” says Meyyappan.

Take, for example, a handheld sens-

ing unit that airport security personnel

might use. To help the sensor perform

accurately, the device would require a

preconcentrator to concentrate the

incoming mixture of the gas or vapor

being sensed. “You may need a small

micropump or a fan or a blower to

pump this in. You need a signal pro-

cessing chip, as well,” says Meyyappan.

The sensors’ low power consumption

is also an important factor. “It’s not like

you have a wall socket on Mars that

you can just plug into and use any

amount of power,” says Meyyappan.

These sensors can be expected in

production in three to five years.

“Companies are already talking to us

about licensing this technology,” says

Meyyappan.

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Creating nanostructures—transistors—of a much higher density with very

high throughput is a growing need, says Vinayak Dravid, a professor in the

department of materials science and engineering at Northwestern University.

Processing for pervasive devices and small distributed systems is fueling this

demand.

In addition, today’s computer-chip manufacturing processes aren’t fault tol-

erant (any flaw or defect has the potential to break down the system). Nanoscale

lithography techniques, on the other hand, have the potential to produce fault-

less or fault tolerant chips.

These flaws appear in the physical process of making computer chips. “Our

research is in the area of creating tools and devices that can analyze structures

and defects at the atomic level,” says Dravid.

According to Dravid, many engineering challenges are associated with really

translating this research into high-level production chips with high through-

put—not fundamental scientific challenges, but challenges in putting the tran-

sistors together at that small a scale. Although numerous other engineering

challenges exist, positioning structures at the sub-50-nanometer (nm) length

is the biggest problem. “That truly reaches the limits of current lithography

technologies,” says Dravid.

Still, chips are built at the 50-nm scale today. And, according to Dravid, there

is a fair bit of optimism that it can be scaled down two times in the next five

years. “So, we are looking at 20 to 25 nm in that time frame,” he says, adding

that there have been demonstrations of proof of concept down to a handful of

nanometers, but those are still in the laboratory.

WHY SMALLER IS BETTER

In the longer term, NASA’s nanotech

research has applications in the med-

ical arena, such as using carbon nan-

otubes to develop an x-ray source. Such

an x-ray source could then be used to

develop x-ray tubes. These tubes are

useful in x-ray spectrometers and could

have applications in the security

(replacing airport x-ray machines) and

biomedical fields, says Meyyappan.

Research is also under way in using

nanocomputers to maintain healthy

human cells. “A human cell has a dual

function,” says Alexander Yabrov, pro-

fessor of biological research at Rutgers

University. “It functions according to its

ownneeds;italsofunctionsaccordingto

the needs of the organism. Good health

exists when the needs of the organism

and of the cell are optimally satisfied.”

Yabrov proposes using nanosized

computers in the bloodstream to mon-

itor and care for human cells. Accord-

ing to Yabrov’s vision, a physician

would trace, monitor, and maintain

balanced cell health through informa-

tion the nanocomputers gather. He sees

applications appearing as early as two

years out.

Diagnosis also benefits such fields as

agriculture. Northwestern’s Dravid sees

this application arriving in the next

three to five years. Nanosensors could

be used to monitor the health of crops

and livestock.

“To be able to diagnose a threat

ahead of time requires that you have

tools and techniques to detect single

molecule antigens,” says Dravid. Diag-

nostics and sensing is clearly an area

where nanotechnology will have one of

the first and most immediate impacts,

according to Dravid.

W

herever nanotechnology appears

in relationship to data, the need

to gather and process that data exists.

Pervasive computing at the nanotech

level will fill much of that need.

NEWS

JANUARY–MARCH 2006

computing

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