(378e) 3D, Shape-Specific, Scalable, Micro-Fabricated Particle Production Via Roll-to-Roll Printing and Continuous Liquid Interface Production (r2rCLIP)

Particle fabrication on the hundreds of micrometers to nanometer scale has gained interest in the past several decades with a broad potential range of applications from advanced biomedical devices and drug delivery to intrinsic materials interests in microfluidics, granular systems, and abrasives. Well-studied approaches exist including grinding, emulsification, precipitation, and nucleation-and-growth; however, these techniques inherently yield limited control over geometric complexity and uniformity. To address these shortcomings, several new approaches have arisen including direct lithography, single-step roll-to-roll soft lithographic approaches like PRINT (Particle Replication in Nonwetting Templates), and multi-step lithography approaches like SEAL (StampEd Assembly of polymer Layers) with demonstrated scalability and application in bioanalytics and drug delivery. Further fabrication control is accessed through additive manufacturing (AM), enabling industrially scalable complex geometries and tunable mechanical properties. Particle fabrication via flow lithography and two-photon polymerization (TPP) yield high throughput and high spatial resolution, respectively, but have proven limited in concurrently achieving complex geometries, timely production, and regio-specific chemical composition. High-resolution continuous liquid interface production (CLIP) enables polygeometric, permutable, material versatile particle production at an ultimate feature resolution of 1.5 μm. We report a novel, roll-to-roll high-resolution CLIP (r2rCLIP) process for scalable, shape-specific, micron-scale particle production. The r2rCLIP system is demonstrated through increasing geometric complexity, scalability, and intra-print permutability to form moldable, multistep moldable, and non-moldable geometries at ≤ 200 µm unit size. r2rCLIP is shown to achieve versatility through a 200 µm unit size range and geometric variation within a singular print; geometric complexity up to non-moldable, unreachable hollow inner cavities; and fabrication speeds of up to 527, 200 µm unit particles per minute (9 particles / second). Gram-scale, complex geometry, particle fabrication with inherent amenability to a wide variety of resin chemistries can thus be achieved on the day-scale for translatable biomedical and analytical applications.