Study of moiré grating fabrication on metal samples using nanoimprint lithography

Abstract

A moiré grating is a basic optical component used in various moiré methods for deformation measurement. In this study, nanoimprint lithography (NIL) was proposed to produce high frequency moiré gratings on metal samples. A new type of NIL mold and a hot embossing system were developed to overcome the poor flatness and roughness of metal samples. This three-layer mold based on nickel grating was unbreakable, and the self-developed hot embossing system used a bellows cylinder to satisfy the parallelism requirement of grating fabrication on metal samples. In order to generate high quality moiré patterns, the grating profile of the mold was optimized. Then, 1200-3000 lines/mm frequency gratings were successfully fabricated on the different materials such as SiO2, aluminum and stainless steel. In order to evaluate the quality of the replication, the distortion in the fabricated SiO2 grating was analyzed by an inverse moiré method. As an application, the replicated grating on the aluminum sample in combination with the moiré interferometry was used to measure the tensile deformation of the sample. The successful experimental results demonstrate the feasibility and reliability of nanoimprint lithography to produce gratings on metal samples.

The Grid Method for In‐plane Displacement and Strain Measurement: A Review and Analysis

“…At a higher scale, pitches of some tenths of μ m to some μ m can be obtained by various techniques such as nanoimprint lithography . With the so‐called electron beam moiré technique, the lines of the reference grid are ‘drawn’ on the substrate by using the electron beam of a scanning electron microscope (SEM) , or milled using a focused ion beam .…”

Geometric phase analysis based on the windowed Fourier transform for the deformation field measurement

“…Recently, combining with the advanced fabrication techniques of high-frequency gratings [8][9][10], GPA has been widely used in the deformation measurement at micro-and nano-scale [11][12][13][14][15][16][17]. The traditional GPA method, referred to as FT-GPA in this paper, is based on the relationship between the displacement and the phase difference.…”

Deformation grating fabrication technique based on the solvent-assisted microcontact molding

“…There are several approaches to fabricate highfrequency gratings on a specimen, including holographic photolithography [9], electron beam lithography (EBL) [10], focused ion beam (FIB) lithography [11], and nanoimprint lithography (NIL) [12]. However, these methods all involve certain drawbacks, which limit their applications in optical methods.…”