Wearable power sources for wearable electronics are limited by the size of garments.
With that in mind, researchers at Case Western Reserve University have developed flexible wire-shaped microsupercapacitors that can be woven into a jacket, shirt or dress.
By their design or by connecting the capacitors in series or parallel, the devices can be tailored to match the charge storage and delivery needs of electronics donned.
While there’s been progress in development of those electronics–body cameras, smart glasses, sensors that monitor health, activity trackers and more–one challenge remaining is providing less obtrusive and cumbersome power sources.
“The area of clothing is fixed, so to generate the power density needed in a small area, we grew radially-aligned titanium oxide nanotubes on a titanium wire used as the main electrode,” said Liming Dai, the Kent Hale Smith Professor of Macromolecular Science and Engineering. “By increasing the surface area of the electrode, you increase the capacitance.”
Dai and Tao Chen, a postdoctoral fellow in molecular science and engineering at Case Western Reserve, published their research on the microsupercapacitor in the journal Energy Storage Materials this week. The study builds on earlier carbon-based supercapacitors.
A capacitor is cousin to the battery, but offers the advantage of charging and releasing energy much faster.
How it works
In this new supercapacitor, the modified titanium wire is coated with a solid electrolyte made of polyvinyl alcohol and phosphoric acid. The wire is then wrapped with either yarn or a sheet made of aligned carbon nanotubes, which serves as the second electrode. The titanium oxide nanotubes, which are semiconducting, separate the two active portions of the electrodes, preventing a short circuit.
In testing, capacitance–the capability to store charge–increased from 0.57 to 0.9 to 1.04 milliFarads per micrometer as the strands of carbon nanotube yarn were increased from 1 to 2 to 3.
When wrapped with a sheet of carbon nanotubes, which increases the effective area of electrode, the microsupercapactitor stored 1.84 milliFarads per micrometer. Energy density was 0.16 x 10-3 milliwatt-hours per cubic centimeter and power density .01 milliwatt per cubic centimeter.
Whether wrapped with yarn or a sheet, the microsupercapacitor retained at least 80 percent of its capacitance after 1,000 charge-discharge cycles. To match various specific power needs of wearable devices, the wire-shaped capacitors can be connected in series or parallel to raise voltage or current, the researchers say.
When bent up to 180 degrees hundreds of times, the capacitors showed no loss of performance. Those wrapped in sheets showed more mechanical strength.
“They’re very flexible, so they can be integrated into fabric or textile materials,” Dai said. “They can be a wearable, flexible power source for wearable electronics and also for self-powered biosensors or other biomedical devices, particularly for applications inside the body.”
The Latest on: Wearable electronics
via Google News
The Latest on: Wearable electronics
- Stretchable, highly conductive film promising for wearable electronicson November 29, 2019 at 7:01 am
To be suitable for use as wearable electronics, a material needs to be both stretchable and conductive. It should also be breathable and durable. Finding a material that satisfies all four criteria is ...
- Wearable Electronics Products Market Growing Popularity and Emerging Trendson November 28, 2019 at 4:02 am
Nov 28, 2019 (HTF Market Intelligence via COMTEX) -- Global Wearable Electronics Products Market Research Report 2018 is latest research study released by HTF MI evaluating the market, highlighting ...
- Supercon Talk: Sophy Wong Is Designing The Future Of Wearable Technologyon November 27, 2019 at 11:40 am
During her talk “Made With Machines: 3D Printing & Laser Cutting for Wearable Electronics” at the 2019 Hackaday Superconference in Pasadena, Sophy walked attendees through the design process that ...
- Wearable Medical Devices Market Global Overviewon November 27, 2019 at 2:30 am
The top companies in the global wearable medical devices market are VitalConnect, Xiaomi Technology Co., Ltd, Activinsights Ltd., Samsung Electronics Co. Ltd., OMRON Corporation, Fitbit, Inc., Polar ...
- Screen Printed Passives and Interconnects on Bio-Degradable Medical Hydrocolloid Dressing for Wearable Sensorson November 25, 2019 at 2:19 am
Reliability tests were also performed on the printed passives by assessing their impedance while mechanically deformed. This test is crucial for confirming the reliability of the fabricated wearable ...
- NanoEDGE: Nano-based wearable electronics for mental disorder diagnosis and functional restorationon November 25, 2019 at 1:51 am
Such ultra-thin electrodes combined with low-cost skin electronics will form a new generation of wearable sensors. With these sensors, the sophisticated detection of biological signals that are ...
- Stretchable Electronics, Polymer Layers Key to Wearable Multifunction Medical Patchon November 22, 2019 at 8:07 am
Stretchable, flexible electronics are an attractive component for skin-attached sensors and monitors. A team at the Georgia Institute of Technology (Georgia Tech) has developed these electronics ...
- Wearable Fitness Electronics and Technology Market to Show Strong Growthon November 20, 2019 at 11:30 am
Nov 20, 2019 (HTF Market Intelligence via COMTEX) -- HTF MI presents an in-depth overview of the Global Wearable Fitness Electronics and Technology Market Study, detailing the latest product / ...
- Making tiny antennas for wearable electronicson November 20, 2019 at 5:57 am
When it comes to electronics, bigger usually isn't better. This is especially true for a new generation of wearable communication systems that promise to connect people, machines and other objects in ...
- Transformative Electronics Systems to Broaden Wearable Applications | IDTechEx Research Articleon November 18, 2019 at 2:59 pm
The transformative electronics consist of a special gallium metal structure ... making it stretchable, flexible, and wearable. The gallium metal then solidifies again once the structure is peeled off ...
via Bing News