Comparison of Microscale Rapid Prototyping Techniques

Recent advances in manufacturing techniques have opened up new interest in rapid prototyping at the microscale. Traditionally microscale devices are fabricated using photolithography, however this process can be time consuming, challenging, and expensive. This paper focuses on three promising rapid prototyping techniques: laser ablation, micromilling, and 3D printing. Emphasis is given to rapid prototyping tools that are commercially available to the research community rather those only used in manufacturing research. Due to the interest in rapid prototyping within the microfluidics community a test part was designed with microfluidic features. This test part was then manufactured using the three different rapid prototyping methods. Accuracy of the features and surface roughness were measured using a surface profilometer, scanning electron microscope (SEM), and optical microscope. Micromilling was found to produce the most accurate features and best surface finish down to similar to 100 mu m, however it did not achieve the small feature sizes produced by laser ablation. The 3D printed part, though easily manufactured, did not achieve feature sizes small enough for most microfluidic applications. Laser ablation created somewhat rough and erratic channels, however the process was faster and achieved features smaller than either of the other two methods.