National Institute of Standards and Technology,
Keywords: focused ion beam, nanofabrication, silicone replication, nanofluidics, separation, nanoparticles
Summary:The replication of complex nanostructures in soft materials not only enables their mass production for commercial applications, but also broadens their utility in diverse fields involving biological materials. We previously reported the focused ion beam milling and replica molding of complex nanostructures with subnanometer resolution of vertical dimensions. We demonstrated structure–property relationships of dielectric films for interferometry of device dimensions and integration of spectroscopic optics, and nanofluidic slits for analytical separation of fluorescent nanoparticles by size exclusion with subnanometer resolution down to particle diameters of approximately 20 nm. Here, we replicate such devices in soft materials with nanometer resolution of vertical dimensions over a range of 200 nm, and we demonstrate their essential functionality of structural integrity. These fabrication and manufacturing advances will fulfill the potential of our devices for analytical separation of biological nanoparticles such as exosomes in this newly extended size range.