Surfaces patterned with polymer brushes have an important role in many applications, from microarrays and smart surfaces to tissue engineering. The properties of these patterned surfaces can be tuned by controlling the monomer composition, polymer height, and brush distribution across the surface. Therefore, there is a pressing need for printing methods that combine the feature resolution of modern lithography with advanced polymerization chemistries and that can independently vary the monomer composition. Currently, there is no available printing tool is capable of controlling simultaneously polymer height and polymer composition at each position, while producing features with micrometer-scale dimensions. Here we describe a new technique for printing multiplexed arrays of polymer brushes, termed Polymer Brush Hypersurface Photolithography,1 which produces polymeric pixels by independently controlling x and y position on the surface, monomer composition along a polymer brush, and polymer height of each pixel with micrometer precision. The printer is equipped with a light-emitting diode (LED) that projects light (405 nm) onto a CPU-controlled digital micromirror device (DMD) that possesses ~750,000 individually addressable mirrors. These mirrors, reflect the light onto an underlying surface with spatiotemporal control to create patterns via surface-initiated polymer photochemistry. In an effort to create stimuli-responsive surfaces, the polymerization kinetics of two different monomers, the thermoresponsive monomer N-isopropylacrylamide (NIPAM) brushes and thermally inert N,N-dimethylacrylamide (DMA) were studied. The swelling/collapsing transitions of the two polymer brushes were tested. Subsequently, 5D and 6D hypersurfaces were created that revealed different images when heated or when exposed to UV light.2

Stimuli-responsive 6-dimensional polymer brush hypersurfaces

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.