https://english.news.cn/20240111/8050a8cfd6424502873e1b2a0de85c39/c.html

https://www.science.org/doi/10.1126/sciadv.adk6301

A tiny, battery-free and wireless soft swimming robot can detect contaminants and pathogens in confined spaces. The miniaturized mobile electronic system is powered with external radio frequency signals and can sense temperature, and detect and quantify chloride, ammonium and SARS-CoV-2 virus particles in water passing through narrow pipes that are difficult to reach. Simultaneously, the in-situ measurements can be transmitted, via near-field communication, to a nearby smartphone for readouts.