Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
?
EE Times-Asia > Manufacturing/Packaging
?
?
Manufacturing/Packaging??

Conductive ink on textiles yields stretchable electronics

Posted: 30 Jun 2015 ?? ?Print Version ?Bookmark and Share

Keywords:University of Tokyo? stretchable electronics? printed electronics? conducting ink?

A team of researchers from University of Tokyo has developed an ink that can be printed on textiles in a single step to form highly conductive and stretchable connections. According to them, the discovery will enable electronic apparel such as sportswear and underwear incorporating sensing devices for measuring a range of biological indicators such as heart rate and muscle contraction.

Current printed electronics, such as transistors, LEDs and solar panels, can be printed on plastic or paper substrates, but these substrates tend to be rigid or hard. The use of soft, stretchable material would enable a new generation of wearable devices that fit themselves to the human body. However, it has proved difficult to make an ink that is both highly conductive and elastic without a complicated multi-step printing process.

Now, professor Takao Someya's research group at the University of Tokyo's graduate school of engineering has developed an elastic conducting ink that is easily printed on textiles and patterned in a single printing step. This ink is comprised of silver flakes, organic solvent, fluorine rubber and fluorine surfactant. The ink exhibited high conductivity even when it was stretched to more than three times its original length, which marks the highest value reported for stretchable conductors that can be extended to more than two and a half times their original length.

Using this ink, the group created a wrist-band muscle activity sensor by printing an elastic conductor on a sportswear material and combining it with an organic transistor amplifier circuit. This sensor can measure muscle activity by detecting muscle electrical potentials over an area of 4cm x 4cm with nine electrodes placed 2cm apart in a 3 x 3 grid.

Electrodes, wires and via holes can be printed by a single step printing process

Electrodes, wires and via holes can be printed by a single step printing process. The muscle activity sensor was produced by printing once on each side of the material's surface. Image copyright: 2015 Someya Laboratory.

"Our team aims to develop comfortable wearable devices. This ink was developed as part of this endeavour," said Someya. "The biggest challenge was obtaining high conductivity and stretchability with a simple one-step printing process. We were able to achieve this by use of a surfactant that allowed the silver flakes to self-assemble at the surface of the printed pattern, ensuring high conductivity."

- Jean-Pierre Joosting
??EE Times Europe





Article Comments - Conductive ink on textiles yields st...
Comments:??
*? You can enter [0] more charecters.
*Verify code:
?
?
Webinars

Seminars

Visit Asia Webinars to learn about the latest in technology and get practical design tips.

?
?
Back to Top