Tag Archives: flexible

Flexible battery eyes next-gen wearables

Rice University researchers have created a flexible battery that could potentially power future generations of wearable devices. 

Developed by Rice chemist James Tour and his colleagues, the design comprises flexible material with nanoporous nickel-fluoride electrodes layered around a solid electrolyte.


The flexible power source delivers battery-like supercapacitor performance, combining the best qualities of a high-energy battery and a high-powered supercapacitor – without the lithium found in current commercial batteries.

According to Rice postdoctoral researcher Yang Yang, the electrochemical capacitor is about a hundredth of an inch thick, although it can be scaled up by increasing the size or adding layers. In terms of slimming down the battery, Tour believes standard manufacturing techniques will likely allow the battery to become even thinner. 

In tests, the students found their square-inch device held 76 percent of its capacity over 10,000 charge-discharge cycles and 1,000 bending cycles.

As Tour notes, his team set out to find a material that offered the flexible qualities of graphene, carbon nanotubes and conducting polymers – all while possessing significantly higher electrical storage capacity typically found in inorganic metal compounds. Unfortunately, inorganic compounds have, at until recently, lacked real flexibility.

“This is not easy to do, because materials with such high capacity are usually brittle,” he said.


“And we’ve had really good, flexible carbon storage systems in the past, but carbon as a material has never hit the theoretical value that can be found in inorganic systems, and nickel fluoride in particular.”

Yang expressed similar sentiments.

“Compared with a lithium-ion device, the structure is quite simple and safe. It behaves like a battery but the structure is that of a supercapacitor,” he explained. “If we use it as a supercapacitor, we can charge quickly at a high current rate and discharge it in a very short time. But for other applications, we find we can set it up to charge more slowly and to discharge slowly like a battery.”

To create the battery/supercapacitor, Tour’s team deposited a nickel layer on a backing, subsequently etching it to create 5-nanometer pores within the 900-nanometer-thick nickel fluoride layer (facilitating a high surface area for storage).


Once the researchers removed the backing, they sandwiched the electrodes around an electrolyte of potassium hydroxide in polyvinyl alcohol. Testing found no degradation of the pore structure even after 10,000 charge/recharge cycles. Similarly, the scientists confirmed no significant degradation to the electrode-electrolyte interface.

“The numbers are exceedingly high in the power that it can deliver and it’s a very simple method to make high-powered systems,” Tour added. “We’re already talking with companies interested in commercializing this.”

Atmel-powered Printoo featured on Gigaom, EDN

Printoo – powered by Atmel’s ATmega328 microcontroller (MCU) – is a lineup of paper-thin, low-power boards and modules that offer Makers and devs new levels of creative flexibility.

The open source platform, created by the Ynvisible crew, made its official Kickstarter debut last week and has already been covered by a number of prominent publications, including EDN, Gigaom and Quartz.

“A spin-out from YDreams, Ynvisible was founded in 2010 with the goal to bring more interactivity to everyday objects and surfaces, mostly through the use of flexible and printed electronics including the company’s fully transparent electrochromic display. The paper-thin display, which only becomes visible when activated can easily be integrated with different background graphics,” writes EDN’s Julien Happich.

“Running Arduino software, the first Printoo packs include novel printed modules including LED light strips from VTT lab, 1.5V printed batteries from Blue Spark and Enfucell, 0.350mm thin organic photodetectors from ISORG, printed polymer solar cells from Mekoprint, and Ynvisible’s own transparent printed displays running from 1.5V. Also included are modules like Bluetooth LE, DC motor control, flexible LED matrixes, and a variety of sensors. The Printoo core is powered by the Atmel ATmega328 microcontroller.”

As Gigaom’s Signe Brewster notes, printed circuits are currently being considered for everything from shipping labels to tiny spacecraft NASA might send to Mars.

“Ynvisible expects Printoo to find a home among 3D printer owners and DIYers already familiar with Arduino,” Brewster explains.

“The modules are small enough to slip into a 3D printed object, opening up ways to easily create robots and other moving or connected devices. They could also be worn as a bracelet or sewn into clothes.”

Meanwhile, Lio Mirani of Quartz points out that bendable electronics could be the future of the rapidly evolving Internet of Things (IoT).

“When the first Harry Potter movie came out in 2001 the idea of the Daily Prophet, a newspaper that contains moving pictures, qualified as magic. A Kickstarter campaign by Ynvisible, a Lisbon-based technology firm, is bringing that magic to life with its displays, held together with paper-thin circuitry,” writes Mirani.

“Ynvisible’s ‘vision’ is to ‘bring everyday objects to life.’ For that to happen, it isn’t just processing power that needs to get cheaper and smaller, which it has, but the input and output mechanisms also need to be smaller and easily adaptable. Ynvisible is betting there is a broad market for such technology. The roaring success of its Kickstarter campaign is an early validation of that belief.”

Indeed, Ynvisible has already raised close to $36,000 – with support from almost 300 backers. Interested in learning more? You can check out the project’s official Kickstarter page here.

A thermoelectric generator for wearables?!

The upcoming generation of wearables is expected to be lighter and more flexible. Future devices may also be equipped with an advanced power source, which could be a portable, long-lasting battery or even a generator. 

Indeed, as Professor Byung Jin Cho of The Korea Advanced Institute of Science and Technology (KAIST) notes, supplying power in a stable and reliable manner is one of the “most critical issues” for the successful commercialization of wearable devices.


As such, Cho, a professor of electrical engineering, developed a glass fabric-based thermoelectric (TE) generator that is extremely light, flexible and even produces electricity from the heat of the human body. 

In fact, the TE generator is so flexible that the (allowable) bending radius of the generator is as low as 20 mm. Effectively, this means there are no changes in performance – even if the generator bends upward and downward for up to 120 cycles.

To date, two types of TE generators have been developed based either on organic or inorganic materials. The organic-based TE generators use polymers that are highly flexible and compatible with human skin, ideal for wearable electronics. The polymers, however, have a low power output. 

In contrast, inorganic-based TE generators produce a high electrical energy, but they are heavy rigid and bulky.

Essentially, Professor Cho came up with a new concept and design technique to build a flexible TE generator that minimizes thermal energy loss, yet maximizes power output. 

His team synthesized liquid-like pastes of n-type (Bi2Te3) and p-type (Sb2Te3) TE materials – printing them onto a glass fabric by applying a screen printing technique. The pastes permeated through the meshes of the fabric and formed films of TE materials in a range of thickness of several hundreds of microns. As a result, hundreds of TE material dots (in combination of n and p types) were printed and well-arranged on a specific area of the glass fabric.


According to Cho, the TE generator boasts a self-sustaining structure, eliminating thick external substrates (typically made of ceramic or alumina) that hold inorganic TE materials. These extraneous substrates have traditionally consumed a significant portion of thermal energy, causing low output power.

“For our case, the glass fabric itself serves as the upper and lower substrates of a TE generator, keeping the inorganic TE materials in between,” said Cho.
 “This is quite a revolutionary approach to design a generator. In so doing, we were able to significantly reduce the weight of our generator (~0.13g/cm2), which is an essential element for wearable electronics.”

When using KAIST’s TE generator (with a size of 10 cm x 10 cm) for a wearable wristband device, the device is capable of producing approximately 40 mW electric power based on the temperature difference of 31 °F between human skin and the surrounding air.


“Our technology presents an easy and simple way of fabricating an extremely flexible, light, and high-performance TE generator. We expect that this technology will find further applications in scale-up systems such as automobiles, factories, aircrafts and vessels where we see abundant thermal energy being wasted,” added Cho.

Interested in learning more about wearables? You can check out our article archive on the subject here.

Bend your mind with Atmel’s XSense contest

We all know that bendable, flexible touchscreens are the future, and here at Atmel, we consider ourselves to be riding the crest of that curve with XSense, our high-performance, ultra-flexible touch sensor which allows for some crazy shaped, touch-able devices.

Go to any tech website today, and you’ll see the same ol’, same ol’ curved touchscreen phones and tablets. Cool stuff, but we can’t help feeling there’s got to be something more creative out there.

That’s why we’re inviting you to push past previous touch boundaries and create curved, pliable surfaces for anything you could imagine.


Sure, we have some ideas about how WE would use curved, flexible touchscreens. We want to hear what YOU would build with touch unleashed.

The sky’s the limit when it comes to creativity on this one, folks, so go crazy!

The top 10 creative ideas get automatically entered to become finalists and eligible for a grand prize of $1500!

But, better yet, if you reckon you could actually build whatever it is you’ve just thought up, there’s extra prize money on the line.

While you don’t need technical expertise to win our creative contest, if your design is built firmly around our Atmel Design Contest Sensor Specifications, you could win our XSense technical design contest for an additional $1500.

Or, if you’re feeling lazy, you can just browse other people’s designs and vote for your favorite. Easy!

A flexible LIMBERboard for Makers

LIMBERboard – powered by Atmel’s versatile ATMega168  – is targeted at the rapidly growing DIY Maker Movement which is currently shaping the wearable future. Created by Infinite Corridor Technology (ICT), the flexible platform is a stretchable, programmable microcontroller (MCU) board with an open source design philosophy.

“LIMBERboard is the perfect tool for wearable projects like health monitors, activity monitors, impact detectors and more,” the ICT crew explained. “The Bluetooth featured in our first iteration also allows you to send data from the microprocessor to a smartphone, making LIMBERboard great for all mobile projects. Despite its many capabilities, we’ve developed LIMBERboard to weigh less than a nickel so it’s ideal for applications that need to be lightweight.”

The market-ready LIMBERboard will be equipped with a mini-USB port and is programmable using Arduino dev tools. Meanwhile, the very first LIMBERboard features an ATMega168 microprocessor, three-axis accelerometer, lithium ion battery, Bluetooth and boasts the ability to flex, fold and twist more than 120,000 times – all while maintaining full functionality.

Interested in learning more about the Atmel-powered LIMBERboard? Be sure to check out the project’s page on Dragon Innovation here. LIMBERboard is currently seeking crowd-sourced funds, with an initial goal set at $40,000.