Most probably, the term “lab-on-a-chip” came into the public domain with a nice publication that appeared in Scientific American in 2007. That paper focused on recent developments in tiny and portable chips for rapid testing in blood samples for pathogens or biological weapons [1]. The article emphasized microfluidics as a key feature of the chip in order to make the lab-on-a-chip practical. The use of air pressure or electricity is presented as the way to move and precisely manipulate microscopic droplets through tiny chemical-reaction chambers [1]. This sentence shows us the intimate connection between lab-on-a-chip and bioelectronics: we need electronics for precisely manipulating microscopic droplets that contain pathogens or biological weapons. More than that, we also need on board a quantitative technique for quantifying the pathogens or the toxic agents. Therefore, biosensors are immediately involved. Figure 35.1 schematically shows this deep interconnection addressed by modern systems: a platform on a silicon chip that hosts a complex network of microfluidic chambers and channels operating differently, and intimately integrated with a complex microelectronic system. The whole system presents loading ports for injection of samples and reagents. The loaded materials are then mixed and pushed to the first reaction chamber by compressed air (as in point 1 of Figure 35.1) or by electrical or magnetic fields. The reaction chamber performs thermal cycles to assure PCR (polymerase chain reaction) amplification (point 2 in Figure 35.1). In principle, a similar reaction chamber in the chip may perform other chemical reactions required by the assay (e.g. combination with another molecule to extract the target molecule from a complex). Then the reagent products are further moved into another reaction chamber to let a second reaction occur (point 3). The second reaction may be required by the detection method. For example, a reaction with a label (e.g. gold nanoparticles or fluorescent dyes) may be provided in the case of labelled detection. Finally, the marked products arrive in the analysis chamber, and the products are detected (point 4). In the example of Figure 35.1, the detection is provided by a series of diodes that detect the pathogens as well as by electrophoretic tests.