Two-photon direct laser writing enables the fabrication of shape-changing microstructures that can be exploited in stimuli responsive micro-robotics and photonics. The use of Liquid Crystalline Networks (LCN) allows to realize 3D micrometric objects that can contract along a specific direction in response to stimuli, such as temperature or light. In this paper, the fabrication of free-standing LCN microstructures is demonstrated as graphical units of a smart tag for simple physical and optical encryption. Using an array of identical pixels, information can be hidden to the observer and revealed only upon application of a specific stimulus. The reading mechanism is based on the shape-change of each pixel under stimuli and their color that combine together in a two-level encryption label. Once the stimulus is removed, the pixels recover their original shape and the message remains completely hidden. Therefore, an opto-mechanical equivalent of an "invisible ink" is realized. This new concept paves the way for introducing enhanced functionalities in smart micro-systems within a single lithography step, spanning from storage devices with physical encryption to complex motion actuators.
Liquid Crystalline Network Microstructures for Stimuli Responsive Labels with Multi‐Level Encryption / Donato, Simone; Nocentini, Sara; Martella, Daniele; Kolagatla, Srikanth; Wiersma, Diederik S.; Parmeggiani, Camilla; Delaney, Colm; Florea, Larisa. - In: SMALL. - ISSN 1613-6810. - STAMPA. - (2023), pp. 0-0. [10.1002/smll.202306802]
Liquid Crystalline Network Microstructures for Stimuli Responsive Labels with Multi‐Level Encryption
Donato, Simone
Membro del Collaboration Group
;Martella, Daniele
Membro del Collaboration Group
;Wiersma, Diederik S.
Membro del Collaboration Group
;Parmeggiani, Camilla
Membro del Collaboration Group
;
2023
Abstract
Two-photon direct laser writing enables the fabrication of shape-changing microstructures that can be exploited in stimuli responsive micro-robotics and photonics. The use of Liquid Crystalline Networks (LCN) allows to realize 3D micrometric objects that can contract along a specific direction in response to stimuli, such as temperature or light. In this paper, the fabrication of free-standing LCN microstructures is demonstrated as graphical units of a smart tag for simple physical and optical encryption. Using an array of identical pixels, information can be hidden to the observer and revealed only upon application of a specific stimulus. The reading mechanism is based on the shape-change of each pixel under stimuli and their color that combine together in a two-level encryption label. Once the stimulus is removed, the pixels recover their original shape and the message remains completely hidden. Therefore, an opto-mechanical equivalent of an "invisible ink" is realized. This new concept paves the way for introducing enhanced functionalities in smart micro-systems within a single lithography step, spanning from storage devices with physical encryption to complex motion actuators.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.