Facile Fabrication of Electrospun Nanofiber Membrane-Integrated PDMS Microfluidic Chip via Silver Nanowires-Uncured PDMS Adhesive Layer

Abstract

Although direct electrospinning has been frequently utilized to develop a nanofiber membrane-integrated microfluidic chip, the dielectric substrate material retards the deposition of electrospun nanofibers on the substrate, and the rough surface formed by deposited nanofibers hinders the successful sealing. In this study we introduce a facile fabrication process of an electrospun nanofiber membrane-integrated polydimethylsiloxane (PDMS) microfluidic chip, called a NFM-PDMS chip, by applying the functional layer. The functional layer consists of a silver nanowires (AgNWs)-embedded uncured PDMS adhesive layer (SNUP), which not only effectively concentrates the electric field toward the PDMS substrate, but also provides a smooth surface for robust sealing. The AgNWs in the SNUP play a crucial role as a grounded collector and enable approximately 4X faster electro-spinning than the conventional method, forming a free-standing nanofiber membrane. The uncured PDMS adhesive layer in the SNUP maintains the smooth surface after electrospinning and allows the rapid and leakage-free bonding of the NFM-PDMS chip using plasma treatment. A practical application of the NFM-PDMS chip is demonstrated by culturing the human keratinocyte cell line, HaCaT cells. The HaCaT cells are well grown on the free-standing nanofiber membrane under dynamic flow conditions, maintaining good viability over 95% for 7 days of culture.