Nanoimprint Technology: Recent Progress and Applications

Nanoimprint Lithography (NIL) has emerged as a promising nanopatterning technology in recent years. NIL uses a hard mold to mechanically deform the polymer resist material to create nanoscale patterns, which completely free itself from the resolution-limiting factors such as light diffraction or beam scattering that are often inherent with other more traditional approaches. Our recent work have shown that it can be extended to patterning on flexible substrate, on topographies, as well as forming 3D polymer nanostructures via a reverse imprinting process (Fig. 1). By combining the nanoimprint approach with conventional photography, we developed a new technique that can pattern various feature sizes in a single step and simplify the process significantly (Fig. 2). The nanoimprint technique not only has the ability to pattern precise nanoscale features, it is also compatible with polymer material processing. Based on these characteristics, we have applied nanoimprinting to several polymer based photonic devices, including nanostructures in nonlinear optical polymers, highresolution OLED pixels, and polymer waveguide devices. For the latter devices, we will discuss a specific type, namely polymer micro-ring resonators, fabricated by a direct imprinting technique (Fig. 3), and its new application for biochemical sensing.