Self-assembling of liquid crystal droplets on lithium niobate substrates driven by pyroelectric effect

It is known that one of the major attractive feature of liquid crystals (LCs) lies in the fact that their optical properties can be modulated by electric, optical or magnetic fields. Recently, we discovered that liquid crystal droplets, in particular conditions, can be driven in desired locations following electric field lines [1]. But we don't apply an external voltage to generate them, the use of electrodes would be very invasive. We instead exploit the pyroelectric properties of the periodically poled lithium niobate (PPLN) crystal, used as substrate. In fact, heating and/or cooling this material, it has already been demonstrated that surface charges can appear, by pyroelectric effect, leading to very interesting phenomena [2,3]. Then, being our LC a polar molecule, it undergoes a force due to the existing fields, able to move the material. © 2013 IEEE.