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System Performance | System Description | Case Study |
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System Performance
Liquid crystal structures align their particles when an electrical current is applied. This characteristic enables the optical axis of its molecules to change in a few milliseconds, resulting in a change of the system’s optical properties when it is turned on. Unlike other liquid crystal systems, in CLCs transparency is always maintained. The combination of liquid crystal films with polarizers makes it possible to complement this feature with changes in color, broadening the range of possible light performance. Depending on the crossing angle of the polarizers, several colors can be achieved, which, when combined with different intensities of electrical input, results in a variety of shades. CLCs are generally red, purple, violet or blue in their off state because of their polarizers and will change to a clear state when the system is switched on. Some are blue-green, yellow-green, yellow and orange in their off state and will become dark when turned on. All of them have intermediate states between their on and off states, which allows their spectral selective properties to be adjusted (within the visible and infrared ranges). This, in turn, enables a refined control of solar gains, glare, shading and privacy. If sensors and actuators are implemented, CLCs can be set to perform automatically and to interact dynamically with the environment.
The system is still in a research and development stage with a pending patent in the US. For a more advanced lighting analysis and project specific results, we recommend using the Lightsolve program (under development). |
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Performance data for all systems in the same category. Comparison to systems in other categories, selected through the matrix filtering process.
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System Description
This system consists of three elements: the actual CLC material, which is a multilayered thin film sandwiched between two transparent supports (glass or plastic), a microcontroller and a software interface. The CLC film itself uses two polarizers (made using a beam-splitting or an absorptive process), two clear sputtered electrodes (continous or pixilated), and a double-twisted nematic liquid crystal layer. The individual colors and shades can be chosen using different crossing angles between the two polarizers. The prototype dimensions of each independent cell of this film are 55mm in height, 28mm (2.2” and 1.1”) in width, and 3 millimetres in thickness. The real surface’s dimensions range between 6.75 m2 and 2.7m2 . This system has a maximum working temperature of 60 degrees centigrade; it therefore needs to be protected from overheating by installing it in the inner side of double glass facades that include heat reduction treatment, or by installing it on north-facing façades. The systems can be recycled. Maintenance for this system is the same as for a standard double glazing. |
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