Facilitating Fluid Flow Through Carbon Nanotube Arrays Using 3D Printing

Abstract

Three-dimensional (3D) printing is a novel technology whose versatility allows it to be implemented in a multitude of applications. Common fabrication techniques implemented to create microfluidic devices, such as photolithography, wet etching, etc., can often times be time consuming, costly, and make it difficult to integrate external components. 3D printing provides a quick and low-cost technique that can be used to fabricate microfluidic devices in a range of intricate geometries. External components, such as nanoporous membranes, can additionally be easily integrated with minimal impact to the component. Here in, low-cost 3D printing has been implemented to create a microfluidic device to enhance understanding of flow through carbon nanotube (CNT) arrays manufactured for gene transfection applications. CNTs are an essential component of nanofluidic research due to their unique mechanical and physical properties. CNT arrays allow for parallel processing however, they are difficult to construct and highly prone to fracture. As a means of aiding in the nanotube arrays’ resilience to fracture and facilitating its integration into fluidic systems, a 3D printed microfluidic device has been constructed around these arrays. Doing so greatly enhances the robustness of the system and additionally allows for the nanotube array to be implemented for a variety of purposes. To broaden their range of application, the devices were designed to allow for multiple isolated inlet flows to the arrays. Utilizing this multiple inlet design permits distinct fluids to enter the array disjointedly. These 3D printed devices were in turn implemented to visualize flow through nanotube arrays. The focus of this report though, is on the design and fabrication of the 3D printed devices. SEM imaging of the completed device shows that the nanotube array remains intact after the printing process and the nanotubes, even those within close proximity to the printing material, remain unobstructed. Printing on top of the nanotube arrays displayed effective adhesion to the surface thus preventing leakage at these interfaces.