Design, Analysis and Application of Dynamic Visual Cryptography for Visual Inspection of Biomedical Systems

Health care industry has a growing need for advanced tools that enables the discovery the existence or concentration of biological analytes. In this article a concept of novel cantilever-type microsystem platform in the field of biomechanics using optical technique of image encryption and communication scheme based on computer generated holography is proposed. An image hiding technique based on computer generated holography and dynamic visual cryptography is employed. Dynamic visual cryptography is a visual cryptography scheme based on time-averaging geometric moire. It is used together with Gerchberg–Saxton algorithm and 3D microstructure manufacturing techniques to design the optical scheme. Stochastic moire grating is used to embed the secret image into a cover image. The image can visually decoded by a naked eye – the secret is revealed if the amplitude of harmonic oscillations in the Fourier plane corresponds to an accurately preselected value. The phase information of computer generated hologram is then formed on a piezoelectric cantilever-type microsystem platform using electron beam lithography. It serves as an optical element for visual inspections of dynamical changes in investigated biological environment.