Roll-to-Plate (R2P) nanoimprint lithography (NIL) is an imprinting process that consists of a roller mechanism and a rigid surface plate. The core of the roll-to-plate fabrication unit is a transparent cylinder that houses a UV-source in its center. The self-adhesive transparent template can be mounted on the cylinder to pattern the light-curing resin that is fed into the machine. When the template is in full contact with the resin, the resin is simultaneously cured in the nib. The method is shown below.
By using this approach, Stensborg with the help of the University of Copenhagen has demonstrated the production of microfluidic chips with thiol-ene resins. You can read more about the project here.
The Roll-to-Plate process and light-based curing method are used in the HoloPrint® uniA6 DT; a patented light-curing source is located inside the nanoimprint roller.
Advantages of Roll-to-Plate NIL
A small imprinting area, therefore, less imprinting force is required.
Possibility of using both rigid and flexible base substrates.
An ideal method for experimenting and testing new nanoimprinting topologies before mass production, e.g. testing new materials, type of resin required, processing parameters, pressure, speed, and light intensity.
Roll-to-Plate vs. Plate-to-Plate
Roll-to-Plate NIL requires less imprinting force in comparison to wafer molding/Plate-to-Plate (P2P NIL) due to the smaller nip contact area. A nip imprint reduces issues concerning trapped air bubbles and can have a built-in compensation for variation of material thickness, which improves replication uniformity. Roll-to-Plate NIL has the potential to be superior in quality in some applications.