An international team of scientists from North Carolina State University, Flinders University and South Korea have developed a metallic coating for clothing and wearable textiles that is capable of repairing itself, repelling bacteria and, eventually, monitoring the wearer’s electrocardiogram (ECG) heart signals.

According to the team of scientists, conductive circuits created using liquid metal (LM) particles can enhance the wearable electronics market, resulting in "breathable" electronic textiles featuring so-called connectivity powers for autonomously healing itself even when cut.

Source: Flinders University

The scientists explained that when pressed with force, the LM particles form a conductive path, thereby enabling the formation of circuits that maintain conductivity when stretched.

When cut, the conductive patterns autonomously heal by forging new conductive paths along the edge of the cut, thus demonstrating a self-healing feature that makes these textiles appropriate for use as Joule heaters, circuit interconnects or flexible electrodes for measuring ECG signals, the researchers explained.

To accomplish this, the team dip-coated fabric into a suspension of LM particles at room temperature.

"Evenly coated textiles remain electrically insulating due to the native oxide that forms on the LM particles. However, the insulating effect can be removed by compressing the textile to rupture the oxide and thereby allow the particles to percolate.

"This enables the creation of conductive circuits by compressing the textile with a patterned mold. The electrical conductivity of the circuits increases by coating more particles on the textile" explained the scientists.

Further, the scientists suggest that the LM-coated textiles offer antimicrobial protection against Pseudomonas aeruginosa and Staphylococcus aureus.

With both fluidic and metallic properties, LM has shown promise for use in applications including microfluidics, sensors, soft composites, thermal switches and microelectronics.

The coating is detailed in the article, Liquid Metal Coated Textiles with Autonomous Electrical Healing and Antibacterial Properties,” which appears in the journal Advanced Materials Technologies.