Soft lithography for flexible structural color films by laser interference lithography

Abstract

To face the challenge of the fast, large area, and high-precision manufacturing for flexible structural color films, a strategy based on soft lithography to fabricate polydimethylsiloxane (PDMS) structural color films was proposed in this paper. The large area periodic structures as the template were obtained by means of laser interference lithography. After soft lithography, SEM images showed that the morphology and period are completely inversed with the templates. The colors of the films have an obvious angle dependence which was proved by an angle-resolved spectrometer(ARM), in which the peak position of the reflectance spectrum changed ∼267 nm as the angle increasing from 10° to 25° for the period ∼2.126 μm. In addition, the peaks of reflectance spectra have also an obvious redshift of ∼162 nm with increasing elongation ratio up to 40 %. Furthermore, the reflection peak of the flexible film will stably change between ∼697 nm and ∼617 nm before and after stretching from 0 to 40 % for 11 times. In conclusion, we explore an efficient way with the fast, large area, and high precision to fabricate flexible structural color films in the atmospheric environment, showing the potential application in optical anti-counterfeiting and mechanical sensor.