"Sweat-Proof Wearable Patch: Your Ultimate Electronic Companion"

Imagine a world where your workout clothes can monitor your biometrics and the environment in real-time, giving you instant feedback on your health and the conditions around you. This is no longer a distant dream, thanks to the development of a new wearable electronic patch that is impervious to sweat. In a recent study published in Nature, a team of researchers led by Zhang et al. have created a flexible device that can rapidly discharge sweat, ensuring comfort and stability during prolonged wear.

Current wearable electronic patches face significant challenges when it comes to managing sweat. While some designs use mesh-like electrodes without backing layers for breathability, this makes it difficult to attach the devices to the skin and integrate them with advanced electronics. Other designs incorporate permeable substrates with micrometre- or nanometre-sized pores, but these openings can allow sweat to flow both ways, causing short circuits and corrosion.

To solve these problems, Zhang et al. engineered a wearable electronic patch by combining two liquid diodes - devices that allow liquid to flow in one direction only. The first component, a vertical liquid diode, is made of fabric that is hydrophilic on the top and hydrophobic on the bottom. This gradient in wettability facilitates unidirectional liquid transport, allowing sweat to move from the bottom to the top. A horizontal liquid diode on top of the vertical one uses superhydrophilic micropillars to drive sweat towards the edges of the patch, where it is released from outlets. A ring of polyester fabric between the two layers acts as a sweat collector, ensuring that any electronics integrated into the centre of the substrate remain unaffected by perspiration.

The researchers demonstrated the versatility of the patch by integrating it with various wearable electronic systems that were connected using detachable magnets. For example, when electrocardiogram (ECG) electronics were incorporated into the patch, it adhered to skin better and showed lower levels of signal interference than did existing ECG patches, providing stable heart-rate readings over the course of a week. The authors also showed that they could integrate an electromyography (EMG) device into the patch, allowing for the measurement of electrical activity in muscles.

The potential applications for this technology are vast. For instance, the patch could be incorporated into a T-shirt embedded with electronics that record real-time meteorological parameters, making the garment a wearable weather station. This could benefit outdoor enthusiasts and people working in challenging environments, even in heavily humid or rainy conditions. The patch could also be used in medical settings to monitor patients' biometrics or to deliver drugs through the skin.

While further research is needed to make the current design suitable for extreme conditions, the potential for this technology is immense. The ability to create high-performance wearable patches or smart textiles that contain complex electronic components is an exciting prospect, bringing us one step closer to a world where our clothes are not just fashionable but also intelligent.

Source: <https://www.nature.com/articles/d41586-024-00789-z>