Researchers have developed a new conductive ink that could be used to create electronic wearable apparel.

The innovative ink could be printed onto material in single step, forming a "highly conductive and stretchable" electronic connection that could lead to the development of sportswear that senses biological functions such as heart rate, the University of Tokyo reported.

Currently, printed electronics can be attached to plastic or paper substrates, but cannot be applied to more flexible material. The ability to print electronic ink onto stretchable material could lead a new generation of wearable devices that can be fit to the human body.

A team of researchers created an elastic conducting ink that can be easily printed on stretchable material in one simple step. The ink is made from silver flakes, organic solvent, fluorine rubber and fluorine surfactant. The incredible ink proved to exhibited high conductivity even when it was stretched

The researchers created a wrist-band muscle activity sensor by printing the ink onto an elastic material and combining it with an organic transistor amplifier circuit. The device was able to measure muscle activity by detecting muscle electrical potentials.

"Our team aims to develop comfortable wearable devices. This ink was developed as part of this endeavor," said Professor Takao 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."

The findings were published in a recent edition of the journal Nature Communications.