Figure 1
From: Electrically tuning soft membranes to both a higher and a lower transparency
State-of-the-art strategies to achieve DEA-based devices with electrically tuneable optical transparency: (a) expansion of a soft membrane with wrinkled stretchable transparent electrodes; (b) cratering-type surface instability of a constrained soft membrane with transparent electrodes; (c) alignment of liquid crystals encapsulated within a soft matrix sandwiched between transparent electrodes. With strategy (a), at electrical rest the wrinkled electrodes cause extensive scattering of the transmitted light, whilst a voltage-induced surface expansion flattens the wrinkles, thereby increasing the transparency. With strategy (b), the transparency of the device at electrical rest is reduced by an applied voltage, due to electromechanical instabilities that form craters, which scatter light. With strategy (c), at electrical rest the twisted liquid crystals scatter light, whilst voltage-induced alignments of the crystals increase the transparency. Note: the change of membrane thickness resulting from the actuation of each device is not shown for simplicity.
