Photolithography and nanoimprint lithography-based SiNx membrane filters applied to the isolation of bovine milk exosomes via electrophoretic oscillation

In this study, a 6-inch SiN_x nanoporous filter was fabricated by combining nanoimprint lithography (NIL) and photolithography. This process enables precise pore size control and uniform pore distribution through front-side nanopatterning and back-side photolithography and ensures high stability even in large-scale mass production. The produced filters were used to separate bovine milk-derived exosomes (average size 110nm). The existing tangential flow-based ultrafiltration (TF-DU) method had a problem of filter clogging due to large biomolecules. However, electrophoretic oscillation (EO) technology was introduced to prevent pore clogging and improve purification efficiency. The isolated exosomes were obtained without modification while maintaining their spherical structure and biological stability. This technology can be applied to various fields, including drug delivery, disease diagnosis, and therapeutic drug development. It is attracting attention as a mass-production solution with excellent scalability and cost-effectiveness.