Microfluidic Manufacturing Technique: Xurography
Microfluidic Lab on a chip (LOC) technology opened the possibility of handling very small volumes, bringing about the opportunity to analyze samples that were previously beyond our reach.
In addition, it has proven to have the capacity to increase both speed and sensitivity, which combined with the fact that it is a tool on the same scale as the single cell and many fundamental biological processes makes LOC a well suited tool for investigation and manipulation of these processes.
During the last decade, there has been enormous amount of research towards finding the best material, simplifying fabrication techniques, improving biocompatibility and miniaturizing the device scale in order to develop devices which are more efficient, cheaper, faster, and have a higher throughput. In this framework, the need for a fabrication tool that speeds up the research work becomes clear.
Xurography is a prototyping technique that employs a knife plotter to structure thin foils.
This technique uses a cutting plotter traditionally used in the sign industry for cutting graphics in adhesive vinyl films
Manufacturers specify the resolution of the cutting plotters in terms of mechanical and addressable resolution. The mechanical resolution specifies the resolution of the motors, while the addressable resolution is the programmable step size.
There are three types of cutting methods, and the specific one is chosen as a function of the application.
– Drag knife: Drag knife cutting uses a swivel blade that follows the cutting path of the feature as it moves relative to the material. This introduces lateral force from the blade at sharp feature corners, which can break the tip when cutting harder or thicker substrates.
– True tangential: Controls blade position with an addressable motor. When cutting corners, the blade lifts completely out of the material and rotates to the new direction. Line segments can be over-cut to ensure the material is completely cut from top to bottom at feature corners. This is useful when cutting thick materials.
– Emulated tangential: Uses a swivel blade but lifts the blade just to the surface of the material before pivoting on the tip at a feature corner. This reduces lateral force on the blade. Over-cuts in emulated tangential plotters bring the blade into position before initiating a cut and ensure feature corners are completely severed from the rest of the material.