Hitachi has started producing what they call SPD technology – “suspended particle device” technology – is in fact one of the coolest things I have ever seen.  Okay, imagine this – a film that can be added to windows and other light transmitting surfaces that allows light to be transmitted when voltage is applied to the film.  You’d be imagining Hitachi’s new film product.

When this product is in its voltageless state, it is a deep blue – as voltage is applied, it becomes clear.  The concept is pretty beautiful, and perhaps even sexy in practice.  The product has a matrix of electrically reactive particles that are oriented in such a way that when voltage is applied they allow light to pass through them easily, and when they have no voltage, they are not oriented and appear deep blue.  The concept is like an electrochemical set of louver doors in a way – here’s a technical explanation:


The new film consists of two polyethylene terephthalate (PET) films coated with a transparent conductive layer and matrix resin dispersed with microcapsules that contain oriented particles. And the matrix resin is sandwiched by the PET films.

When voltage is not being applied, the particles are not oriented and their color is navy blue, thus shielding light. When alternating voltage is applied to the oriented particles, the particles become oriented and transparent.

Pretty sweet, right?  Can you imagine about eleventy quadrillion uses for this already?  Something else that might rock to know is that the film consumes about 1 watt per square meter – not bad.  Could probably improve, especially when you consider covering a skyscraper in this stuff!

Thanks, TechON!

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  1. Awesome…lots of uses I would imagine but can you be more specific about its uses in the entertainment lighting field?

    • Thanks for commenting, Bill!

      The biggest element I can see in entertainment lighting might be scenic applications – reveals in windows and doors, scenic forms, set pieces, that kind of thing. I could definitely see this application being added to low heat fixtures like fluorescent boxes as an interesting dimmer-esque device.

      Got any other ideas? I’d love to hear them!

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