Optical fiber sensors based on nanoscale self-assembly

The Electrostatic Self-Assembly (ESA) method is a new process that has been successfully tested for the deposition of coatings on glass, silicon, polymer or metallic substrates. This technique allows to control the individual layer composition and the thickness of the coatings on the nanometer scale and has been already proved on substrates with different sizes and shapes such as prisms, curve lens or fibers. The molecular species of the nanolayered structures and the long-range physical order of the layers determine the resulting coating properties. Combining the proper materials it is possible to build up sensitive coatings onto optical fibers for the measurement of humidity, harmful gases, volatile organic compounds or pH. These sensitive films can have thicknesses from 1 nanometer to 1 micron. Here, a review of the different optical fiber sensors fabricated up-to-date using the the ESA process is presented. The promising results obtained as well as the new possibilities opened by the synthesis of the new multilayered materials using the ESA method are also studied.