A tiny and very delicate lens iris was created
German researchers have created a tiny and very thin lens iris, much smaller than existing mechanical irises, paving the way for a new generation of tiny cameras for 'smart' mobile phones and tablet computers.
The smart glass
The innovative iris, which is made of a new electrochromic material, the polymer PEDOT (also called "smart glass"), is electro-chemical and not engineering like today's, which allows for a significant reduction in its size. In addition, it has very low power consumption, which makes it ideal for a wide range of portable battery and camera electronics.
The polymer was developed by researchers at the University of Kaiserslauten who used a material arranged in concentric consecutive rings, which transform from transparent to opaque when passed through a low-power electric ρεύμα (επειδή αλλάζει Colour under the influence of electricity, the material is called electrochromic). The micro-iris, just 55 micrometers (millionths of a meter) thick, runs on just 1,5 volts, which doesn't even need to be continuous for the material to remain opaque, as it has a "memory."
The mechanism
In the human eye, the iris controls the pupil diameter and thus the amount of light entering the retina. In cameras the role of the iris is essentially the same, controlling the diaphragm opening and hence the amount of light that reaches the sensors.
Traditionally, cameras use mechanically driven lens irises, which adjust according to lighting conditions and the photographer's wishes. But as cell phone cameras become more popular and lighter, it becomes more difficult to shrink these mechanical parts, as they have approached their natural size limit. This is precisely why the new discovery is important, paving the way for electro-chemical lens irises without mechanical parts. The discovery is published in the Journal of Optics.
Source: tovima.gr
