Fig. 6: Proof-of-concept demonstration of silicon-based nano-kirigami structures for optical information encryption.
From: Silicon nano-kirigami with controlled plastic, elastic and hysteretic deformations
a SEM images of a SOI pattern encoded with the capital letters “SOI”. The spiral patterns in the letter area are composed of (i) Archi-270 spirals, while the other area is composed of (ii) Archi-240 spirals. b In-situ microscope images of the same SOI pattern when turning on the voltages of 0, 90, 130, and 200 V, respectively, showing the voltage-dependent deformation properties. c In-situ microscope images of the four distinctive states of the “SOI” pattern during the charge and discharge process at 210 V. The four states are consistent with those in Fig. 5c, d. Under this high voltage, the encoded information can only be displayed after turning off the voltage for toff = 1 s due to the hysteretic deformation. d In-situ microscope images of the “SOI” pattern at the hysteretic deformation state after prolonged exposure to a high voltage of 170 V with durations of ton = 5, 15, 30, and 1800 s, respectively, with no damage observed. e SEM images of a pattern encoded with capital letters “SONIC”. The letter “SOI” area is composed of (i) Archi-270 spirals, and the “NC” area consists of (ii) Archi-240, while the other area is formed by (iii) Archi-210 spirals. f Microscope images of the encoded “SONIC” pattern displayed under a voltage of 150 V for 600 s. Under this voltage, elastic deformation occurs, and the structure returns to its initial state after turning off the voltage. g In-situ microscope images of the encoded “SONIC” pattern with an applied voltage of 210 V. At the on state, the full letters “SONIC” are displayed due to the elastic deformation, while at the off state, only letters “SOI” are displayed due to the hysteretic deformation and the different stiffness of nano-kirigami designs. Scale bars:10 µm.
