Now, 'smart glass' micro-iris to take smart-phone cameras to next level

The researchers from University of Kaiserslautern have created a micro-iris from a 'smart glass' material and hope their invention will take the smart-phone cameras to the next level.

The micro-iris is an electro-chemical equivalent to the bulky, mechanical blades that are usually found in cameras and has very low power consumption, making it an ideal component for a wide-range of camera-integrated consumer devices.

Traditionally, cameras have contained a set of overlapping blades that are mechanically moved to change the size of the aperture, through which light enters. However, with the rising popularity of small, compact and lightweight consumer devices that are integrated with cameras, it has been almost impossible to miniaturise these mechanical systems.

The researchers have proposed an alternative method using an electrochromic material, often referred to as 'smart glass', which transforms from a transparent material into an opaque material when a small electrical voltage is applied to it.

In their study, the researchers fabricated a micro-iris using two glass substrates sandwiched together, and with each one carrying a thin film of electrochromic material, called PEDOT, on an underlying transparent electrode.

The micro-iris was 55 micrometer thick and could be switched into an opaque state using a current of 20 microampere with a voltage of 1.5 V. It exhibited a memory effect and did not require a continuous current to maintain the opaque state, so its power consumption remained very small.

Tobias Deutschmann, lead author of the research said that currently there was no technological solution available that meets all the demands of integrated iris apertures in smartphones. Electrochromic materials, as used in this study, remain stationary whilst they change their absorption, so there is no need for any actuation.

This allowed for much smaller casings to fit around the devices and thus enables the integration into tiny camera systems, he added.

The study is published in IOP Publishing's Journal of Optics.