Professor Chongwu Zhou and his team of researcher at the University of Southern California produced flexible transparent carbon atom films that have great potential for a new breed of solar cells suitable to be integrated into garments.

Graphene OPV (organic photovoltaics) has been on the research agenda for a couple of years as means to transport electronics from hard substrate PCB (Printed Circuit Board) to soft, flexible substrates suitable to be wrapped around curved surfaces or even in clothing.

Professor Zhou’s lab reported the large scale production of graphene films by chemical vapor deposition three years ago. In this process, the USC engineering team creates ultra thin graphene sheets by first depositing carbon atoms in the form of graphene films on a nickel plate from methane gas.

These OPV films convert solar radiation to electricity, but not as efficiently as silicon cells like in rigid or the flexible solar cells commercially available today.

The power provided by sunlight on a sunny day is about 1000 watts per square meter. ‘For every 1000 watts of sunlight that hits a one square meter area of the standard silicon solar cell, 14 watts of electricity will be generated,’ says Lewis Gomez De Arco, a doctoral student and a member of the team that built the graphene OPVs.

Organic solar cells are less efficient; their conversion rate for that same one thousand watts of sunlight in the graphene-based solar cell would be only 1.3 watts. It is not as bad as this numbers suggest. Assuming this technology can be further developed into volume production with reasonable low costs, large areas could be covered with OPV films which are not suitable for rigid, planar surfaces.

OPV solar cell technology is yet another promising step into wearable power technologies of the future but as most of these developments at research stage, it will take a (very) long time until one of these hot technologies will make it into the commercial consumer market.

[source: Eurekalert via Printed Electronics World]

Most wearable electronic development we see today are made by attaching either permanently or removable electronic functionality. This concept has it’s usefulness in some areas but the ultimate break through in wearable electronic will be by fully integrating electronics into fabrics from which clothing is made.

Fabrics are made by weaving yarns of different types and colors. So wearable electronics will be the most important elements in wearable electronic development.

ETH Zurich is one of the leading institutes in wearable technology research and development since the early days of wearable electronics. A recently published research project by Scientists from Professor Gerhard Tröster’s Wearable Computing Lab developed a new technology to attach thin-film electronics and miniaturized, commercially available chips to plastic fibers.

The first electronic fabric patches produced are still ribbon-like but the researchers aim to produce intelligent textiles in any size so they can be cut as required to satisfy the requirements of the clothing industry.

These Electronic fibers can contain miniature sensors together with the necessary processing electronics building a smart, self-contained system in one string. Weaving them into fabric structures allow advanced electronic functionality of the fabric itself without relaying on attached or external hardware. Just connect power to these smart fabrics and these textiles come to life.

The research team is confident that such fabricated smart fabrics can be mass-produced on conventional looms and the woven structures are washable up to 30 degree Celsius.

This all sounds very promising and as I mentioned at the begin, a much needed step towards fully integrated wearable technology.

[source: ETH Zurich]

Staying a bit in the fiber since field today’s article is about a development coming from Jian Feng Gu at the Huazhong University of Science and Technology in China.

Mr. Jian Feng Gu and his team work on a simple rolled capacitor from a sheet of conducting polymer sandwiched between two insulating sheets of low density polyethylene.

They then roll this sandwich into a cylinder and encase it in high density polyethylene. next they heat it and then extrude it through a tiny hole to form a fiber with a diameter of less than a millimeter.

If the conditions are just right, the plastics all stretch in exactly the same way so that the internal structure of the fibre is a smaller version of the original.

The result would be a fiber that is soft and flexible and has a capacitance some 1000 times greater than an equivalent co-axial cable. With such super fiber, fabrics can be woven to make garments serving as electrical power storage, power collected from piezoelectric fibers or flexible solar panels integrated into such garments.

Research into advanced, technical textile fibers are the cornerstone of the future of smart clothing. Attaching electronic components as we see right now is a interesting, exploratory step towards the full integration of functionality into fibers, the building block of fabrics and at the end clothing in many different forms.

[source: Technology Review]

In the old days making fibers was a relative simple matter, creating yarn and weave them to clothes. But these days are numbered with the emergence of intelligent fibers and textiles.

Fiber development migrated in our digital age to electronic laboratories like MIT’s Research Lab of Electronics where Associate professor of Materials Science, Yoel Fink is working on fibers able to pick up sound and to act as speaker.

Yoel Fink and his collaborators announced in the August issue of Nature Materials the passing of a new milestone in their development: fibers that can detect and produce sound.

The magic element in the new acoustic fiber is a plastic commonly used in microphones, also known as piezoelectric microphone, which means that it changes shape when an electric field is applied to this plastic material.

In a fiber microphone, the drawing process would cause the usually used metal electrodes to lose their shape. So the researchers instead used a conducting plastic that contains graphite, the material found in pencil lead. When heated, the conducting plastic maintains a higher viscosity, yielding a thicker fluid than a metal would.

This sounds very interesting but keep in mind, it’s not as easy as it reads in this few lines and it will take some time to figure out a way to produce hearing and singing fabrics.

Nevertheless, possible applications are already on the radar for the research team, applications ranging from wearable microphones and biological sensors to large-area sonar imaging systems with ultra high resolution: A fabric woven from acoustic fibers would provide the equivalent of millions of tiny acoustic sensors.

Another sexy application would be to combine the textile microphone capabilities with color changing fabric technology. The result would be garments that react on surrounding acoustic by altering its colors in sync with natures sound.

[source: MITnews]

Assistant professor of materials science and engineering at Stanford Yi Cui and his team have manufactured a new energy storage device (battery) out of ordinary paper or cloth coated with carbon nanotube ink.

Sounds fantastic news for wearable power especially as this process can be made cheaply and efficiently manufactured into lightweight paper or textile batteries and supercapacitors which act like batteries to store energy but by electrostatic rather than chemical means like in conventional batteries.

The paper supercapacitor could offer up to 40,000 charge-discharge cycles compared to around 500 cycles of todays lithium-ion batteries.

Mr. Cui’s invention of  a ‘magical power powder’ applied to textiles could transform an inner-liner of a jacket into a wearable battery, a foldable, stretchable power source for the devices we have in our pockets (or bags).

Wearable power, one of the hottest research areas today might still be a futuristic dream but each new research release comes a step closer to the technical and manufacturing feasibility.

Mr. Cui demonstrates in the video below how easy and simple his invention can transform ordinary paper into an electrical energy storing device.

This type of paper/cloth battery would be a perfect candidate for eTexile application.

[source: Stanford University News]

A topic that goes one step further than Wearable Electronic: Implantable Electronic. Wearable of course but this new field of electronics g=does not stop on the skin, it goes under the skin.

For me, implantable electronic is as fascinating as wearable electronic as both aim to use cutting edge technologies to improve life quality. Wearable technologies in medical application, although a by far not really explored area, offers clearly demonstrable benefits.

Implantable Electronic in the medical field can be used for monitoring of vital signs like blood test and even could deliver pharmacy directly to the areas needed avoiding the ‘flush out’ treatment usually used today.

Tufts University biomedical engineer Fiorenzo Omenetto uses silk as the basis for implantable optical and electronic devices that could provide a clearer picture of what’s going on inside the body to help monitor chronic diseases or progress after surgery.

Collaborating with Kaplan and materials scientist John Rogers at the University of Illinois at Urbana-Champaign, Omenetto has produced implants that combine silk with flexible silicon electronics.

The group used silk films to hold in place arrays of tiny silicon transistors and LEDs, forming a possible basis for implantable devices. The advantage of the teams invention: it will degrade completely inside the body when the job is done unlike previously developed implants which have to be removed making incisions.

Implantable Electronic seems to be the next frontier, pushing the boundaries of wearable skin deep. A field I will certainly keeping an eye on in future reporting.

[TechnologyReview via GizmoWatch]

On a fairly regular basis researchers publish new findings around power generating textiles, a topic highly interesting for the wearable electronic community.

This time engineers at the University of California, Berkeley, created energy generating nanofibers that could one day be woven into textiles.

The nano-sized generators work on the ‘piezoelectric’ principle, converting kinetic energy through stretches and twists into electricity.

Sounds fabulous as the textiles of our clothing stretches and twists all day when worn.

‘This technology could eventually lead to wearable smart clothes that can power hand-held electronics through ordinary body movements,’ said Liwei Lin, UC Berkeley professor of mechanical engineering and head of the international research team that developed the fiber nanogenerators.

The nanofibers are made from organic polyvinylidene fluoride, or PVDF, they are flexible and relatively easy and cheap to manufacture.

Oh yeah, in almost all of these announcements, this new technology is easy and cheaply to manufacture. We heard this from flexible solar cells as well some years back but up until today, the cheap factor has not materialized.

It’s always exiting to see advances in developments and research but all this has to be taken with a (very) long term view as such break-through discoveries, although they seems simple to make, can take a long time to become robust enough to produce in quantities and then to become affordable to be actually used in everyday objects like clothing.

Let’s put the Fiber Nanogenerators on our watch-list but move on with technologies and materials we have today and use them smartly to create smart clothes now.

[source: Science Daily]

A recently published scientific development from researcher at the Imperial College London looks like another stepping stone towards wearable power.

The scientists created a super-capacitor in a flexible form by sandwiching a glass-fiber layer between two layers of carbon fibers which are covered with electricity conducting resign.

Super-capacitor, widely used in electronic products, have the property to be fast charged and dis-charged. They are not batteries but under certain conditions could easily act like short term electrical power storing devices.

The research project is funded by Volvo Car Corporation which sees a potential to use this technology to cover the whole car body with the flexible super-capacitor in future hybrid cars substituting or even replacing heavier, bulkier conventional batteries.

But this flexible super-capacitors could be also useful for wearable applications as they can conform to the body shape when integrated into clothing items.

Another environmental aspect of this new development: this form of electrical energy storing does not use chemical processes like it is the case in batteries, making them longer lasting as the recharging process causes little degradation in the composite material.

It’s energizing to see how ‘old’ technologies made with new materials create components that open the doors for new designs.

[via: DailyMail]

Scientists at Stanford University, CA join the race for wearable power by developing ink from single-walled carbon nanotubes.

According to the scientists, everyday textiles like Cotton or Polyester fabrics can be electrified with an extremely simple “dipping and drying” process resulting in eTextiles with an excellent ability to store electricity.

Conductive ink impregnated textiles retain their flexibility and stretchability and tests show repeated laundering does not negatively effect the power storing ability.

These properties ‘… allow for many applications and designs previously impossible with traditional electronics technology‘ Yi Cui and colleagues note. ‘High-performance sportswear, wearable displays, new classes of portable power, and embedded health monitoring systems are examples of these novel applications.‘

Clothing made of such advanced eTextiles can be charged overnight and give off their stored energy to pocket devices or other clothing embedded technologies like illumination or sensors during the day.

As always, research breakthroughs have to be seen on a longer term as it might still take some years to turn laboratory success into commercial success.

Nevertheless, each small or big step is important to finally unleash the power in fashion.

[source ACS via AZoNano]

Wearable electronic is still in it’s early stage, make the first baby steps into the harsh world of commercialization but visionaries and researchers work already on the next big thing in getting electronics closer to our bodies, actually inside our bodies.

Having electronic implants is not new and some people depend their life on it with pacemakers for example. But these developments can also be used for a more playful, fashionable purpose or artistic like the Bare Conductive concept which uses conductive ink to paint circuitry on the skin.

Other companies have patented the human skin to be used for power and data transmission. A handshake can exchange information from one Blackberry to the other in a wearers pocket.

According to a recent Technology Review article, researchers at the Beckman Institute at the University of Illinois, the Tufts University in Medford, MA, and the University of Pennsylvania building thin, flexible silicon electronics on silk substrates that almost completely integrate into the body.

While electronics usually has to be encased to protect it from the body, these electronics don’t need protection. During the implanting the electronics is covered in a silk like substrate which melts away over time and the thin silicon circuits left behind don’t cause irritation because they are just nanometers thick.

The group is developing silk-silicon LEDs that might act as photonic tattoos that can show blood-sugar readings, as well as arrays of conformable electrodes that might interface with the nervous system.

The Skin LEDs have been successfully implanted into mice and now it’s time to find volunteers for the next testing phase.

Electronic giant Philips is exploring the body as platform for electronics as well with their version of an electronic Tattoo, the SKIN:Tattoo which is stimulated by touch. Sensual navigation along the landscape of the body paints tattoo like pattern on the skin.

The good thing about electronic tattoo’s: they can be instantly and painlessly switched off or changed compared to needle and ink tattoo’s – that is, one has to go over the implanting pain first.

For now I am taking a step back and focus on wearable, textile electronic before going under my skin.