In spite of its inferior performance, the cooling applications based on Peltier devices don’t require maintenance because there are no movable parts. The Figure 3 shows a conventional Peltier module, constituted by thermoelectric elements between the two ceramic foils. The ceramic foils must be good thermal conductors to minimize their effect on the performance of the Peltier device. The smallest device (between the wires) is a miniaturized Peltier module made with thermoelectric micropairs is also depicted.