From Additive Manufacturing to 3D/4D Printing 2

2μ-Fluidics (or Microfluidics)

2.1. Introduction

Microfabrication is related to the field of microfluidics and involves the production of microchannels that have diameters of less than a millimeter, therefore necessitating techniques adapted to such sizes. When the process first started, and even nowadays, it has always placed enormous reliance upon microelectronic silicon technologies. The selection of materials used has expanded to other materials such as glass, steel and polymers. Microsystems intended for industrial use (such as micromixers) are made of stainless steel. Carrier [CAR 12] has said that two main technologies known as “hard or soft” are subject to consideration. “Hard technologies (glass, silicon and other materials) are based upon the processes of printing, lithography and matter deposition. Soft technologies (involving elastomers or plastics) are based upon a so-called direct method or replication method.” Microfabrication processes depend, for the most part, on lithography, and in particular photo-lithography [TAB 03] and molding [HAM 08]. An important element is that of the surface finish of ducts in different projects which 3D technology users focus upon [VIL 04, REY 02, BAR 04]. The purpose of this chapter is to analyze competing works targeting the exploitation of additive manufacturing technologies in microfluidic applications.

Figure 2.1 (proven by the works of Ho et al. [HO 15] and of O’Neill et al. [ONE 14]) corresponds to the development of the ...