Stretchable device can lead to `smart` contact lenses

Sydney: A team of researchers including an Indian-origin scientist is working on a device that manipulates light to such an extent that it can filter specific colours while still being transparent and can be used to make “smart” contact lenses.

Researchers at Melbourne-based RMIT University and the University of Adelaide are creating a stretchable nano-scale device to manipulate light.

According to associate professor Madhu Bhaskaran from RMIT, the devices were made on a rubber-like material used for contact lenses.

“We embedded precisely-controlled crystals of titanium oxide - a material that is usually found in sunscreen, in these soft and pliable materials," she said.

The materials are proven to be bio-compatible, forming an ideal platform for wearable optical devices.

“By engineering the shape of these common materials, we can create a device that changes properties when stretched. This modifies the way the light interacts with and travels through the device, which holds promise of making smart contact lenses and stretchable colour changing surfaces,” Bhaskaran explained.

Using the technology, high-tech lenses could one day filter harmful optical radiation without interfering with vision.

In a more advanced version, the lenses can transmit data and gather live vital information or even show information like a head-up display.

“Manipulation of light using these artificial crystals uses precise engineering. With advanced techniques, we can dynamically control their filter properties, which allow us to create devices for high data-rate optical communication or smart contact lenses,” explained Dr Withawat Withayachumnankul from the University of Adelaide.

The current challenge is that dielectric resonators only work for specific colours, but with the new flexible surface, scientists can adjust the operation range simply by stretching it.

According to RMIT researcher Dr Philipp Gutruf, the major scientific hurdle overcome by the team was combining high temperature processed titanium dioxide with the rubber-like material and achieving nanoscale features.

“With this technology, we now have the ability to develop light weight wearable optical components which also allow for the creation of futuristic devices like flexible smartphone cameras," noted Gutruf in a paper published in the journal ACS Nano.