Stretchy sensors can detect deadly gases and UV radiation

Wearable sensor patches that detect UV radiation and toxic gases such as hydrogen and nitrogen dioxide have been created at RMIT, by a team bringing science fiction gadgets closer to real life.

The transparent, flexible electronics can be worn as skin patches or incorporated into clothing.

Dr Madhu Bhaskaran, project leader and co-leader of the RMIT Functional Materials and Microsystems Research Group, said the sensors could be placed on work and safety gear to detect dangerous gases.

“Hydrogen leaks can lead to explosions, as happened with the Hindenburg disaster and nitrogen dioxide is a major contributor to smog,” she said.

“The ability to monitor such gases in production facilities and coal-fired power stations gives vital early warning of explosions, while the ability to sense nitrogen dioxide allows for a constant monitoring of pollution levels in crowded cities.”

The development follows RMIT’s MicroNano Research Facility’s breakthrough in bendable electronics which has paved the way for flexible mobile phones.

Lead author, PhD researcher Philipp Gutruf, said the unbreakable, stretchy electronic sensors were also capable of detecting harmful levels of UV radiation, known to trigger melanoma.

They are able to alert the wearer to harmful levels of UV radiation, which can lead to skin cancer in real-time.

Much like a nicotine patch, they can be worn on the skin.

In future, they will be able to link to electronic devices to continuously monitor UV-levels and alert the user when radiation hits harmful levels – especially useful in Australia with its high UV levels.

Gutruf said the research used zinc oxide – present in most sunscreens as a fine powder mixed into a lotion – as the UV sensing material.

Zinc oxide was used in the form of very thin coatings over a hundred times thinner than a sheet of paper.

“This thin zinc oxide layer is engineered with a plate-like structure that we call micro-tectonics,” he said.

“These plates can slide across each other, a bit like geological plates that form the earth’s crust, allowing for high sensitivity and the ability to bend and flex the devices.”

Bhaskaran said the sensors are cheap and durable – attributes which will see flexible electronics and sensors become an integral part of everyday life.

The research, which was published in leading micro/nano-science journal Small, was supported by the Australian Research Council.

(Source: RMIT, Small)