Virginia Military Institute, based in Virginia, United States, collaborated with Stensborg A/S to explore holographic surface relief structure design and mastering for internal educational and institutional branding applications.
The objective was to demonstrate how nanoimprint lithography can bridge the gap between digital design files and physical nanostructured optical masters, enabling small-scale production of photonic-grade surface structures within an academic environment.
Image credit: Stensborg
Project Objective
The collaboration focused on:
Workflow
This case study illustrates a full nanofabrication chain combining computational design, laser-based interferometric mastering, electrochemical replication, and production based on R2P nanoimprint lithography.
Stensborg supported VMI with the complete project scope, delivering ready-to-use templates made in both metal (nickel) and polymer that could be used for nanoimprint replication in their labs using our Roll-to-Plate compact desktop tool.
1. Digital Pre-Press & Optical Design Translation (Mask Preparation)
The process began with standard digital assets provided by the university (bitmap files). These digital files were then converted into lithographic design formats by Stensborg’s engineering team.
Stensborg’s key optical design transformations included:
A. Colour file data conversion into a first 256 grayscale bitmap file:
Line-resolution data suitable for optical interference patterning, corresponding to grating lines ranging from 1.4 micrometers to 700 nanometers pitch, defining the diffraction colour structure.
B. Directional grating data conversion into a second 256 grayscale bitmap file:
Light interaction parameters are encoded through angular dependencies, controlling how the hologram responds under different illumination angles.
C. Exposure file generation:
Final mask files are prepared for laser interference lithography or electron-beam-based mastering systems
This stage effectively converts graphic design into a photonic instruction set.
2. Mastering: Laser Interference Holographic Nano-Structuring
For this mastering process, a glass substrate is spin-coated with approximately 2 µm photo-sensitive resist.
The prepared files were then exposed using laser interferometry onto a photoresist-coated glass substrate, forming the basis of the optical nanostructure and generating the final pattern in the photoresist master plate (see image below).
3. Master transfer – Intermediate template
A thin conductive layer is deposited onto the photoresist surface, enabling electroforming and uniform metal deposition. The electroforming process is then carried out over several hours, whereafter a separation of the glass plate and electroformed metal reveals a 100% metal copy (reverse polarisation of design) which can be up to several mm thick. This process can then be repeated, producing multiple metal copies from a metal master.
The result is a durable, reusable 100% replicated intermediate master, capable of high-volume replication in downstream nanoimprint processes.
4. Template Production — Metal and Polymer Working Templates
The intermediate metal template produced in Step 3 served as the source for all downstream production of working templates.
The Stensborg Desktop Roll NanoImprinter 3.0 was used to then produce both metal and polymer working templates from the intermediate master, and to run replication copies directly from those templates as a bridge between laboratory-scale optical mastering and industrial replication workflows.
Several secondary electroforming passes were performed to generate a family of nickel working templates in both positive (POS) and negative (NEG) structural polarities, some for producing UV polymer templates, others for producing monolayer polymer templates (and holographic replications samples ) directly in materials such as PMMA, PC, PET, and COC.
Thus, desktop enabled rapid iteration of template development and validation from the replicated master using a roll-to-foil process to transfer the holographic structure into final polymer samples.
Results
This project demonstrates Stensborg’s core value proposition: cost-efficient nanoimprint lithography workflows begin at the earliest development stage, and aligning process steps to a single scalable replication pathway ensures faster, more reliable production.
VMI — Research and Teaching Applications
The Department of Physics and Astronomy at Virginia Military Institute has an established optics and thin films research programme with laboratory infrastructure including AFM characterisation, polarised light microscopy, and a long-standing cadet research tradition in holography and interferometry. The delivered template set supports both active research use, including diffraction studies, nanoimprint replication trials, and material compatibility testing, and direct integration into teaching and cadet laboratory programmes.
“In the development of the generation 3 of our Desktop, we focused on control, monitoring, and data integrity so that nanoimprint processes can be developed under conditions that match industrial manufacturing.”
This workflow is directly applicable across multiple high-growth sectors: diffractive gratings, waveguide optics, microlens arrays, and holographic diffusers for advanced light shaping and display technologies; light-trapping nanostructures, anti-reflective coatings, and solar cell surface texturing to improve photovoltaic efficiency; and microfluidic lab-on-chip systems for medical applications. By enabling institutions to directly convert design files into physical nanostructures through a compact system, Stensborg positions itself not only as an equipment provider, but as a full-stack nanomanufacturing enablement platform… bridging research, prototyping, and industrial scaling.
