This conductive ink can make your clothes smarter

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University of Tokyo researchers have created a new ink that can be printed on textiles in a single step.

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As the dream of a world with everyone wearing smart clothing continues to become a reality, University of Tokyo researchers have developed a new conductive ink that will enable electronics to be printed on stretchable fabrics.

(Source: Someya Laboratory/University of Tokyo)

“Current printed electronics, such as transistors, light-emitted diodes, 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,” the team led by Professor Takao Someya explains.

The ink can be easily printed on textiles and patterned in a single step. This is made possible through the combination of fluorine, an organic solvent and silver flakes, which when mixed, maintains its electricity even if stretched to more than three times its original length. As you can imagine, this makes it ideal for smart athletic apparel that monitors things like heart rate and movement.

Using their new ink, the researchers have developed their first prototype — a wristband muscle activity sensor — by printing an elastic conductor on a sportswear material and blending it with an organic transistor amplifier circuit. While it may not replace your fitness tracker just yet, the sensor can measure muscle activity by detecting muscle electrical potentials over an area of 4×4 square centimeters with nine electrodes placed 2 centimeters apart in a 3×3 grid.