007_EETE

EETE APRIL 2013

edition of the Z5 supports both CDMA2000 (800MHz, for China Telecom) and WCDMA (2100MHz, for China Unicom); and when Nubia eventually launches it worldwide, it will be capable of supporting LTE as well. Nubia goes to the U.S. and Russia Nubia’s first-year plan 2013 is dedicated to building a strong Nubia brand in China. “We want to make it as attractive as possible,” said Fei. “China is a tough market. But if we can win China, we can win anywhere in the world.” Later this year, the company will test the waters both in the U.S. by leveraging its operator connections, and in Russia by pursuing a strategy based on channels — which in Russia are more powerful than operators. Nubia was born from a small team of young engineers at ZTE who wanted a phone based on their own dreams – instead of just following operator specs. “There were about 10 of us in the beginning. We worked day and night,” said Fei. “We wanted to design a phone that would make people curious and say, ‘let me try it.’” Today, Nubia’s engineering team has between 300 and 400 employees. Eighty percent are focused on Fig. 2: Nubia CEO, stressing that software is the key, shows off a wallpaper app based on ‘crowd sourcing’. software development, the rest on hardware, according to Fei. Nubia-ZTE synergy? Because Nubia phones and ZTE phones for operators are based on the Android platform, there is a fair amount of shared engineering resources between the two, according to Fei. In fact, the experience, expertise and knowledge accumulated at ZTE’s handset division - where Fei spent seven years before heading up the Nubia group - is giving Nubia a leg up, explained Fei, in terms of partnering with the supply chain, thirdparty app developers and key device vendors like Qualcomm. Nubia’s ZTE connection turns out to be also critical in shortening the time to market for Nubia’s products and ensuring a just about everyone’s attention here these days. That might explain Fei’s less frequent blogs lately, said an industry source who spoke on the condition of anonymity. Fei, a great advocate of social media, said, “You can use Weibo to get your messages out, but you can’t control it.” Flexible battery operational at a 300% stretch By Julien Happich Northwestern University’s Yongang Huang and the University of Illinois’ John A. Rogers have demonstrated what they claim to be the first stretchable lithium-ion battery. The unit remains operational, powering a commercial LED, even when stretched, folded, twisted and mounted on a human elbow. The battery can work for eight to nine hours before it needs recharging, which can be done wirelessly. “We start with a lot of battery components side by side in a very small space, and we connect them with tightly packed, long wavy lines,” said Huang, one of the researchers who published the findings in the online journal Nature Communications. “These wires provide the flexibility. When we stretch the battery, the wavy interconnecting lines unfurl, much like yarn unspooling. And we can stretch the device a great deal and still have a working battery.” The power and voltage of the stretchable battery are similar to a conventional lithium-ion battery of the same size, but the flexible battery can stretch up to 300 percent of its original size and still function. Huang led the portion of the research focused on theory, design and modelling. Rogers, also a corresponding steady supply for key components such as Sony’s CMOS image sensors and Sharp’s full-HD resolution LCD screen, he added. Asked what’s next after Z5, Fei said Nubia hasn’t decided on screen size yet but it is interested in adding a new user interface like gesture controls, by using MEMS. A lot of new features will come from the development of software, he added. “The key is that we must hide technical complexity.” Fei, who is said to have a million followers on Sina Weibo (China’s twitter), acknowledged that he has slacked off on his Weibo blog posts. A series of heated public arguments on Weibo — between executives at Xiomi and rival Huawei about their smartphones — is getting author of the paper, led the group that worked on the experimental and fabrication work of the stretchable battery. For their stretchable electronic circuits, the two created an array of tiny circuit elements connected by metal wire “pop-up bridges.” When the array is stretched, the wires - not the rigid circuits - pop up. For the battery components, Huang’s design solution is to use metal wire interconnects that are long, wavy lines, filling the small space between battery components. The unique mechanism is a “spring within a spring”: The line connecting the components is a large “S” shape and within that “S” are many smaller “S’s.” When the battery is stretched, the large “S” first stretches out and disappears, leaving a line of small squiggles. The stretching continues, with the small squiggles disappearing as the interconnect between electrodes becomes taut. The battery’s design allows for the integration of stretchable, inductive coils to enable charging through an external source but without the need for a physical connection. Source and top image: Northwestern University - www.northwestern.edu 6 Electronic Engineering Times Europe April 2013 www.electronics-eetimes.com


EETE APRIL 2013
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