Novel tunable optical modulation lens using magnetorheological effect

This study extends the fluid dispensing and sealing technology to realize a novel MR fluid lens (MR fluid: liquid polymer with magnetic particles) for light intensity modulation. Merits of the device: Optical transmittance of lens is controlled by (1) weight fraction of magnetic powder, and (2) orientation of columnar particles controlled by magnetic field. In applications, the MR fluid lens is realized on glass substrate and suspended MEMS structures. The light intensity modulation of MR fluid lens (diameter: 2000μm) by magnetic field is demonstrated. Measurements show the NdFeB liquid polymer (10wt%) has a 40% dark area change and 290% laser transmittance difference after applying magnetic field.