or less. Two microfabrication techniques used to create organ-on-a-chip systems are lithography and etching. Lithography is a process that uses light to create patterns on a photosensitive material.

• Soft Lithography: Soft lithography is a microfabrication technique used to pattern highly ordered structures with nanometer resolution. It is based on the principle of capillary forces and uses a combination of mechanical and chemical techniques. This method is relatively inexpensive and easy to use, making it an ideal microfabrication technique for organ-on-chip systems. It is capable of producing complex, multilayer structures, enabling it to be used for the engineering of artificial organs. However, the resolution and accuracy of the patterns produced can be limited and they may degrade over time. • Nanoimprint Lithography: Nanoimprint lithography is a fabrication technique that uses mechanical force to imprint patterned features on a substrate. It is capable of producing high-resolution, highly uniform features with nanometer-scale accuracy. This makes it a suitable choice for the fabrication of organ-on-a-chip systems. Additionally, it is relatively simple and cost effective compared to other microfabrication techniques, making it a desirable choice. However, nanoimprint lithography is limited by the complexity of the structures that can be produced, as the mechanical force may cause the displacement of delicate structures.