Breathable wearables may be worn for a week or longer
Image credit: Someya Laboratory
Researchers from the University of Tokyo have developed nanomesh-based wearables that can be applied like a temporary tattoo and worn for at least a week without causing irritation. These breathable meshes could be the basis of e-skin devices of the future, which can be worn to monitor long-term health.
Wearable electronic devices to monitor important health signals such as heart rate are beginning to pick up in popularity, with many lightweight and elastic gadgets designed to adhere to the skin. These devices enable more sensitive monitoring, although they have proved unsuitable for long-term use.
These fine, stretchy materials can prevent sweating and block airflow around the skin, causing irritation and inflammation which, if sustained, could lead to longer-term physiological damage.
“We learned that devices that can be worn for a week or longer for continuous monitoring were needed for practical use in medical and sports applications,” said Professor Takao Someya, a researcher at the University of Tokyo’s Graduate School of Engineering.
Professor Someya and his research group have previously worked on wearable health monitoring devices, creating an on-skin patch to measure blood oxygen levels. Seeing a need to develop comfortable devices which can be worn for long periods of time, they developed a new electrode from nanoscale meshes.
The meshes contain a water-soluble polymer and biocompatible gold-layer materials. To apply the device, it is held to the skin, and a small amount of water sprayed over it. This dissolves the polymer fibres, allowing it to conform perfectly to the surface of the skin, much like a temporary tattoo. It even conforms to the shape of sweat pores and ridges of the skin.
Next, the team conducted skin patch tests on 20 people, and found that after a week, there were no signs of inflammation or irritation. It was so light and thin, the researchers report, that users were able to forget that they were wearing it.
The device also proved durable through bending and stretching, effective at allowing gas to permeate through the mesh, and as reliable as an electrode for electromyogram recordings, compared with conventional gel electrodes.
“It will become possible to monitor patients’ vital signs without causing any stress or discomfort,” said Professor Someya. The researchers hope that as well as having healthcare applications, the device could also enable continuous and precise monitoring for athletes, without disrupting their training.