(Bio)fabrication of microfluidic devices and organs-on-a-chip

Organ-on-a-chip (OoC) is a class of microfluidic devices for the modeling of organs and organ systems. Such systems can be used for disease or drug testing models with high efficiency, accuracy, and throughput, thus decreasing research expenses and minimizing the necessity for animal experiments. OoC devices rely on microfluidic principles to model the cell and tissue environments in minuscule volumes. In this chapter the general concepts of the OoC are presented, together with the basic principles of microfluidics in the context of design requirements and manufacturing challenges of OoC. Up to recently, most microfluidic devices have been manufactured by MEMS technologies, mainly soft lithography, due to the demand in high resolution and accuracy. Recently, however, 3D printing has gained its share in OoC research, allowing for an increased complexity of the OoC devices and faster transition from a concept to a functional prototype. A typical OoC consists of a microfluidic device body and biological components, precisely located inside of it. Often, it requires the use of different materials and printing modalities, making technology convergence an important topic in OoC manufacturing. Nevertheless, while the range of accessible materials for the suitable 3D printing technologies is widening, multimaterial printing, including printing of living cells has become possible. 3D (bio) printing has already been used for multiple OoC models, including skin, liver, and heart while further technological advances are bringing additional incentives for OoC development.