Reconfigurable Nanophotonic Systems By Tunable Alignment Between Nanomagnet Arrays

Abstract

We demonstrate self-alignment and tunable displacements of released nanopatterned membranes by use of arrays of nanomagnets. The nanomagnet arrays attract and align when brought into close proximity resulting in sub-200nm accurate self-alignment between membrane segments of >50μm lateral size. The alignment is made reconfigurable by patterning the nanomagnets so that there are multiple stable alignment states. An external field is used to transfer between alignment states by applying a magnetic torque on the arrays and by shifting the nanomagnet polarity. Realignment via folding and unfolding of membranes was demonstrated using 75nm thick cobalt nanomagnets patterned on 1um thick silicon nitride membranes. Accurately aligned reconfigurable 2D or 3D nanophotonic systems, such as active photonic crystals and sheared photonic crystal waveguides, may be fabricated with this method.

Dynamic group velocity control in a mechanically tunable photonic-crystal coupled-resonator optical waveguide

“…3 is the lateral displacement actuator required to make the membrane translate, but this can be achieved using a voltage actuated interdigitated comb drive or a magnetic membrane translation scheme. 15 In Fig. 4, we show that a photonic-crystal structure in which only half of the waveguide-row is translated functions FIG.…”

Micro Snap-Fits for Latching 3D MEMS Assemblies

“…Assembling 2D films into 3D structures requires three steps: actuation of the 2D precursors, accurate alignment of the segments, and latching them in their final positions. Actuation methods for assembly are relatively well-developed, including actuation driven by bending moments from stress gradients [2], internal forces such as surface tension [3,4], and external magnetic or electromagnetic forces [5,6]. We have also developed a cascaded alignment system for accurately positioning 2D patterned segments at arbitrary angles in space [7].…”