Researchers from China’s Fuzhou University have created a breathable underwater movement sensor that could potentially detect drowning swimmers.

To create the sensor, the researchers submerged a piece of conductive polyester knit fabric into a solution of graphene oxide and then hydroiodic acid. The fabric was then coated in a thin layer of polydimethylsiloxane (PDMS) — which is a silicon-based organic polymer that is water repellant — microparticles.

Source: ACS NanoSource: ACS Nano

The result was a conductive fabric that is both water repellant and permeable to air and that can be incorporated into a wireless underwater movement detection system, according to its developers.

Once developed, the sensor can reportedly be integrated into a smart device that wirelessly communicates with a smartphone app when a swimmer stops moving — a possible sign of drowning.

In the lab, the fabric-based sensor was combined with a power supply and data collector to create an underwater movement system that wirelessly transmits the electrical response from the movements of the wearer to a smartphone app.

The team attached the underwater movement sensor to a motorized swimming doll in the lab where the app tracked the doll’s kicking legs. When the doll was disabled and its kicking ceased, the app sent an alert.

In addition to monitoring swimmer safety, the underwater sensors could potentially be used to monitor the heart rate of swimmers or to track the activity of swimmers.

The study, A Breathable Knitted Fabric-Based Smart System with Enhanced Superhydrophobicity for Drowning Alarming, appears in the journal ACS Nano.

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