Template based chemical vapor deposition (CVD) is a process of effectively fabricating nanostructures such as Carbon nanotube arrays (CNT). During this process, a carbon-carrying precursor gas is used to deposit a layer of solid carbon on the surface of a template within a furnace. Template-based CVD using porous anodized aluminum oxide (AAO) membranes as the template has been applied to efficiently mass-produce CNT arrays which have shown promise for use in gene transfection applications. These AAO membranes are incredibly fragile, making them prone to cracks during handling which can compromise their performance. In order to ease handling of the CNT devices, three-dimensional (3D) printing has been applied to create a support structure for the fragile membranes. The work presented here focuses on the use of 3D printing as a means of integrating CNT arrays into nanofluidic devices, both increasing their useful application and preventing damage to the fragile arrays during handling. 3D printing allows the CNT arrays to be completely encapsulated within the fluidic device by printing a base of material before inserting the arrays. Additionally, 3D printing has been shown to create an adequate seal between the CNT arrays and the printed device without the need for additional adhesives or sealing processes. For this work, a commercially available, fused deposition modeling (FDM) 3D printer was used to print the devices out of polylactic acid (PLA) plastic. This approach has been shown to be effective and repeatable for nanofluidic device construction, while also being cost effective and less time consuming than other methods such as photolithography. Cell culture and has been demonstrated using HEK293 cells on the devices and was found to be comparable to tissue culture polystyrene.
Substrate adhesion evolves non-monotonically with processing time in millimeter-scale aligned carbon nanotube arrays