**4. Polymeric nanowire architecture as full-color micro/nanodisplays**

Recently, a number of crossed nanofiber structures for full-color micro/nanodisplays has been reported by H. Yu et al. [22] The crossed array structures were formed by assembling flexible PTT nanofibers under an optical microscope with the assistance of micromanipulators while avoiding the use of color filters and complicated photolithography processing. The color pixels of the displays consist of micro/nanometer sized color spots in a radius of 3001500 nm. The colors and sizes of the spots were tuned by changing the total power and power ratios of the launched red, green, and blue (RGB) lights.

As shown in Fig. 26a, a 33 structure was assembled by using nanofibers 1, 2, and 3 with diameters of 558, 598, and 598 nm, respectively, and RGB lights were launched into the nanofibers 1, 2, and 3, respectively, with a total power of 63.4 μW and a power ratio of about 50:13: 10. Inset of Figure 25b shows that a white colour at the centre of the spot with a radius of about 818 nm was observed at the crossed junction. The colour coordinate was (0.41, 0.35). Its correlated colour temperature (CCT) is 3026 K.

**Figure 26.** 33 crossed structure [22]**.** (a) SEM image of the device with diameter of 558, 598, and 598 nm for the nanofibers 1, 2, and 3, respectively. The nanofiber 1 is perpendicular to the nanofiber 2, the cross-angle of the nanofibers 2 and 3 is about 50. (b) Optical microscope image of the guided visible lights in the structure. The inset shows a magnified (5) view of the white spot at the crossed junction. The arrows show the propagation directions of the launched lights. Scale bar in the inset is 20 μm.
