Suspended Particle Devices

Suspended particle devices (SPDs), also called light-valves or light-control particles, are electronically switchable chromogenic devices made of charged electrophoretic rod-shape particles suspended in an organic gel that change their orientation in an applied electric field, thereby enabling rapid voltage-controlled modulation of their optical transmittance. For cost-efficiency, SPD films are typically produced using a roll-to-roll manufacturing process with a typical maximum width of 1.8m. Once an SPD film has been cut to the required size and shape, a lamination process is used to assemble the layers that form an SPD glazing. This process is conducted in a climate-controlled clean room environment. SPD glazing alone or in combination with other systems form part of an envelope system to mediate between the internal and external environments to achieve desired internal comfort, health, and amenity.