Magnetically triggered thin-film instabilities for surface pattern control*

The study under consideration is concerned with instabilities of a thin magnetic film attached to a soft (magnetic) substrate under general biaxial precompression and transverse magnetic fields leading to complex two-dimensional surface patterns. This study builds upon previous experimental work on one-dimensional surface patterns through magneto-elastic loading.
Our findings contribute a key ingredient for the design of haptic displays and more general applications of surface actuation. For the characterization of the instabilities of interest we conduct numerical studies using finite-element and Fourier discretizations for a wide range of in-plane prestresses and applied magnetic field. By virtue of these results we obtain stability maps which are an important input for subsequent numerical and experimental studies in the post-buckling regime.