Solar-powered glasses display information about surroundings on the lenses
Prototype solar-powered glasses with built-in Google Glass-esque displays have been demonstrated by researchers at the Karlsruhe Institute of Technology in Germany.
The device uses coloured, semi-transparent organic solar cells applied onto lenses that supply a microprocessor and two displays with electric power.
Organic solar cells are flexible, transparent and light-weight and can be manufactured in arbitrary shapes or colours.
This makes them suitable for a variety of applications that cannot be realised with conventional silicon solar cells and paves the way for other future applications such as the integration of organic solar cells into windows or overhead glazing.
“We bring solar power to places where other solar technologies fail,” said Dr Alexander Colsmann, Head of Organic Photovoltaics Group at KIT’s Light Technology Institute (LTI).
The ‘smart’ solar glasses are self-powered and measure and display the solar illumination intensity and ambient temperature.
The lenses fit onto a commercial frame, are just 1.6mm in thickness and weigh about six grams.
The microprocessor and the two small displays are integrated into the temples of the glasses.
They show the illumination intensity and the ambient temperature as bar graphs and even work in indoor environments under illumination down to 500 Lux, which is the usual illumination of an office or a living area.
Under these conditions, each of the ‘smart’ lenses still generates 200 milliwatts of electric power - enough to operate devices such as a hearing aid or a step counter.
“The solar glasses we developed are an example of how organic solar cells may be employed in applications that would not be feasible with conventional photovoltaics,” said PhD student Dominik Landerer.
According to Colsmann, another field of application is the integration of solar cells into buildings.
Since the glass facades of high-rise buildings must often be shaded, it is an obvious option to use organic solar modules for transforming the absorbed light into electric power.
Large surfaces could also be coated with organic solar cells using reel-to-reel technology.