Development of a tunable and resealable porous membrane for organ-on-a-chip devices

Abstract

Organ-on-a-chip platforms are a promising technology for research in biotechnology, tissue engineering and pharmaceutical fields. They enable the study of physiological processes, facilitating the development of new drugs and broadening the understanding of the effects of mechanical and chemical cues in different cell lines. A very crucial role in these devices is played by porous membranes, which separate chamber content while allowing substance exchange through micro or nano pores. Additionally, it is the membrane that supports the cell culture and may provide actuation. Available porous membranes however do not possess resealability nor tunability features. This thesis presents a comprehensive review of organ-on-a-chip applications and the role of porous membranes within them, as well as membrane actuation methods and fabrication techniques. It also demonstrates the development of novel tunable and resealable porous PDMS membranes of different thicknesses, fabricated using fast and inexpensive prototyping methods for their integration into microfluidic plastic chips. Membrane deformation and pore opening were studied as a function of liquid flow rate. Pore opening increased with higher flow rates, demonstrating the tunability of pore opening useful for toxicological or pharmacological applications that require controlled transfer of substances or particles between chambers. The proof-of-concept study of a tunable and resealable porous membrane presented in this thesis is expected to motivate future works in smart membranes embedded in organ-on-a-chip devices to increase the system’s representativity and better emulate organs in vitro.