Process could reduce the cost of producing infrared lenses

The development could lead to cheaper thermal-imaging cameras that are currently fitted as a safety feature in luxury cars and can cost up to €2,000 (£1,580).

Such cameras, or microbolometers, detect infrared rays and warn motorists driving in poor visibility of obstructions through an acoustic signal or a warning light.

‘We have developed a production process for lenses that enables us to lower the costs of these components by more than 70 per cent. Thus the prize for the microbolometer could be reduced,’ said Dr Helen Müller, scientist at the Fraunhofer Institute for Mechanics of Materials IWM in Freiburg.

According to a statement, the lenses are normally made out of crystalline materials such as germanium, zinc selenide or zinc sulphide. These materials are expensive and can only be processed mechanically through grinding, polishing or diamond turning to shape them correctly.

‘Instead of crystalline materials, we use the amorphous chalcogenide glass. Its softening temperature — that is, the temperature at which it can be formed — is low,’ said Müller. ‘Therefore, we can form it using non-isothermic hot stamping.’