The unique glass roof can be made either transparent or darkened at the touch of a button.
Transparent mode offers an ‘open-air experience’, while in darkened mode it will mean protective shade for the interior and passengers.
Mercedes-Benz will be the first automotive manufacturer to offer the panoramic vario-roof with Magic Sky Control.
Merceds says the operating principle is based on the physics of a plate condenser: if the glass structure is subjected to an electrical voltage, particles in the structure position themselves so that light is able to pass through the glass. If the voltage remains switched off, however, the particles position themselves randomly. This partially blocks the light, and the glass remains dark. The control unit and converter are integrated into the front section of the roof, and the switch is in the overhead control console.
The glass was tested around the globe, including Death Valley in the USA – one of the hottest places on earth. Under the heat of the sun, summer temperatures there regularly hit over 50ºC in the shade. The test engineers heated up the SLK prototypes with transparent roofs for four hours around midday. They then switched the roofs to non-transparent mode and reportedly noticed immediate relief from the heat. Thermal images showed that temperatures in the region of the head were reduced.
With an open roof, the load from the sun in the heat of Death Valley reached 1000 to 1100W per square metre. With the transparent glass roof it dropped to 200W, and when the roof was switched to darkened mode with Magic Sky Control, it dropped to 40 to 50W – one 20th of the original value.
Some of the strain is also taken off the air-conditioning system, in turn saving on CO2 emissions.