New self-repairing, bacteria-repelling metallic coating for clothing monitors heart

“The conductive patterns autonomously heal when cut by forming new conductive paths along the edge of the cut, providing a self-healing feature which makes these textiles useful as circuit interconnects, Joule heaters, and flexible electrodes to measure ECG signals,” said Flinders University medical biotechnology researcher Dr. Khanh Truong, senior co-author of the new research. 

Dip-coated for efficiency

In order for the coating to work, the fabric must be dip-coated 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,” said Truong in the statement. 

“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.”  

But that’s not all. The new material created by the coating offers effective antimicrobial protection against Pseudomonas aeruginosa and Staphylococcus aureus.  

This quality prevents the treated fabric from becoming contaminated if worn for an extended time, or put in contact with other people.    

The gallium-based liquid metals that coat the fabric come with many advantages, including a low melting point, metallic electrical conductivity, high thermal conductivity, effectively zero vapor pressure, low toxicity, and antimicrobial properties.  

Furthermore, one of the key advantages of LM is that it can be deposited and patterned at room temperature onto surfaces in unconventional ways that are not possible with solid metals. 

The study was first published in Advanced Materials Technologies.

Study abstract: 

Conductive textiles are promising for human–machine interfaces and wearable electronics. A simple way to create conductive textiles by coating fabric with liquid metal (LM) particles is reported. The coating process involves dip-coating the fabric into a suspension of LM particles at room temperature. Despite being coated uniformly after drying, the textiles remain electrically insulating due to the native oxide that forms on the LM particles. Yet, they can be rendered conductive by compressing the textile to rupture the oxide and thereby percolate the particles. Thus, compressing the textile with a patterned mold can pattern conductive circuits on the textile. The electrical conductivity of these circuits increases by coating more particles on the textile. Notably, the conductive patterns autonomously heal when cut by forming new conductive paths along the edge of the cut. The textiles prove to be useful as circuit interconnects, Joule heaters, and flexible electrodes to measure ECG signals. Further, the LM-coated textiles provide antimicrobial protection against Pseudomonas aeruginosa and Staphylococcus aureus. Such simple coatings provide a route to convert otherwise insulating textiles into electrical circuits with the ability to autonomously heal and provide antimicrobial properties.