Lamination of fiberoptical sensors into smart windows for tinting control

The idea of the project is to enable accurate control of the degree of tinting in the so-called dynamic, or "smart", window glass that ChromoGenics manufactures.

The tentative approach is that you can measure how dark the dynamic glass is with fiber optic sensors that are laminated into the glass.

An integration of this kind would mean a technical breakthrough and would significantly increase customer benefit, both in terms of functionality and longevity.ChromoGenics manufactures and develops dynamic glasses with controllable transparency. On hot and sunny days, dynamic glazing can be darkened to prevent solar energy from heating buildings.

In this way, you can save energy through a reduced need for cooling and give increased human comfort.The dynamic glasses can be compared to a thin film battery that is dark when charged and bright when discharged. The solar transmittance can be tuned by controlling the degree of charge through an externally applied voltage.

At high temperatures, however, the glass darkens, even if the voltage is kept constant.

This results in higher light absorption, which further increases the temperature, and the glass darkens more and more.It is because of this complication that the project will investigate whether it is possible to measure how transparent the window is by using optical fibers. It will also be investigated if the temperature can be measured in the glass.

An optical fiber is a thin fiber of glass, normally a little thicker than a hair, that can be used to capture or transmit light.

These fibers can be embedded in the plastic film that is used to laminate the glasses and they then become almost invisible to the naked eye.The project is a collaboration between RISE and ChromoGenics which is planned to run for nine months.

RISE contributes with the development of the fiber optic measurement technology, while ChromoGenics leads the work with lamination of sensors and has a role as a requirement setter and future product owner.