Feeds

Printed diode can slurp power from phone signals

Boffins get smartphones talking to clothes

Providing a secure and efficient Helpdesk

A group of Swedish researchers has created a printed diode that can use the radio output of a smartphone for power – and along the way has answered a long-standing question about how printed diodes work.

In this paper at PNAS, the researchers demonstrate a device created by printing a niobium silicide layer over a silicon paste. Its operating frequency, at 1.6 GHz, is far higher than previous similar efforts – and is fast enough to let the diode work with the kinds of frequencies used by mobile phone transmitters.

As IEEE Spectrum explains, this would let the diode be used to power objects like smart labels.

IEEE Spectrum also notes that other technologies seen as contenders for powering smart labels have cost or fabrication problems that make them impractical. For example, many organic semiconductors are printable, but either work at too low a frequency to operate with smartphone signals as the power source, or need to be deposited under a high vacuum. Nanoparticle semiconducting inks need high temperatures, which make them problematic to print onto clothing labels.

The 1.6 GHz Schottky diode took antimony-doped silicon crushed into particles between 100 nm and 1 micron printed onto an aluminium electrode. The niobium silicide particles were added on top, followed by a carbon electrode and a silver paste. The IEEE article notes that a “brief, mild” heat treatment is needed, but it can be carried out in the open air.

Printed GHz diode

Say hello to your T-shirt: Linköping University's 1.6 GHz printed diode

Linköping University explains while the printed diode has been known of for a long time, its operation has been something of a mystery until the latest work.

The predecessor to the current device was put together at Acreo Swedish ICT in 2001, who followed a process similar to that used in the PNAS study but using just silicon particles. That original device only worked to around 1 MHz, and its operation wasn't well-understood.

The university says PhD student Negar Sani and her collaborators now believe the printed diode uses tunnelling effects: “nano-thin films (1–2 nm) are formed around the micrometer-sized grains of silicon, where the current between anodes (aluminium) and cathodes (silver and carbon) pass through, but only in one direction”, the article states.

Future work will include trying to replace niobium with cheaper materials, and getting a device to operate in the 2.4 GHz band so it can use WiFi and Bluetooth signals.

The work was carried out at Linköping University with collaboration from Acreo Swedish ICT. ®

Internet Security Threat Report 2014

More from The Register

next story
MARS NEEDS WOMEN, claims NASA pseudo 'naut: They eat less
'Some might find this idea offensive' boffin admits
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
America's super-secret X-37B plane returns to Earth after nearly TWO YEARS aloft
674 days in space for US Air Force's mystery orbital vehicle
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
Human spacecraft dodge COMET CHUNKS pelting off Mars
Odyssey orbiter yet to report, though - comet's trailing trash poses new threat
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.