Optofluidic switches and sensors

In the beginning of the 1980s, an intersection of physics, chemistry, and nanotechnology laid the foundation for microfluidics. Microfluidics allowed fast and controlled manipulation of very small volumes of fluid, and these capabilities opened new avenues in optics. The integration of microfluidics with optoelectronic components became known as optofluidics (Psaltis et al. 2006, Monat et al. 2007). This integration throve twofold. First, it allowed the integration of optical components into lab-on-a-chip devices, known also as “micro total analysis systems” (µTAS). Second, it inherited the methods used in microfluidics to build new optical elements and attain new functionalities. In this chapter, we focus on those optical elements and devices that are based on integrated optofluidic components. Throughout this chapter, we use the term fluid in its broad sense, meaning liquid or gaseous phases of substances, and pure or mixed liquids including solutions and colloids.