R2R Nano is a gateway to science and engineering research that aims to impact the widespread adoption of R2R technologies for low-cost, high-volume production of high technology products on flexible substrates. The advanced polymer experts at the University of Massachusetts Amherst specialize in generating ultraprecise imprint masters from self-assembled nanomaterials and in transferring templated patterns with nanometer-scale features to thin film at extremely high accuracy in our world-class test facilities. For R2R to truly transform advanced manufacturing, much basic technical knowledge must still be researched and transferred to industry—this is our mission and our value to the advanced manufacturing community.
Primary Research Areas
The development of cost-effective and robust planarization layers is essential for many applications. UMass Amherst researchers are exploring the use of in-line planarization to achieve 1 nm RMS surfaces as a low-cost alternative to pre-planarized films, while also potentially introducing functionality into the layer.
Imprint Embossing and Patterning
In nanoimprint processing we are working to enable a wide variety of continuous-feed fabrication methods. Critical dimension sizes of imprinted features may vary widely depending upon the application, but we are focusing on optimizing at 50 nm for arbitrary patterns and 1-5 nm for large area nano-texturing for self-assembly. While production speeds of 25 M/min are attainable, speeds up to 1 M/min are envisioned for nanopattern transfer. Other parameters being studied and optimized include pattern aspect ratio, minimization of residual layer, wet and dry etch, adhesion to substrate and release from mold, and substrate variation (PET, PEN, Polyimide, paper).
Alternative Conducting Layers
There is a clear and immediate need for alternative conducting films for device applications especially in the area of transparent conductors. Research is beginning to explore polymer/nanoparticle and polymer/additive systems to achieve coatable films with excellent conductivity.
Many applications require nanometer-scale porosity on a supported or unsupported film. One project involves the use of block copolymer additive systems in which the additive undergoes phase selective chemistry or is used as a porogen that can be selectively removed to generate robust films with well-defined pores.
Functional Hybrid Films
Many applications require thin polymer films whose behavior is defined by additive packages. We are exploring the design and development of polymer/additive films with high loadings of a functional component such as a nanoparticle. Targets include high refractive index films, polymer-based films with high or low dielectric strength and semiconducting films with improved carrier mobility.
Coating of Viscoelastic Fluids
Many applications will require the production of films from coating fluid containing polymer and/or nanoparticle additives. The resulting fluids can become rheologically complex. We are exploring the effect that viscoelasticity has on gravure and slot coating systems so that they can be optimized for use with a wide spectrum of coating fluids.
Our researchers are also interested in roll-to-roll integration issues, design for manufacturability, and fabrication of specific types of devices via roll-to-roll processes.