Chemical sensors are one of the oldest fields of research closely related to the semiconductor technology. From the Ion-Sensitive Field-Effect Transistors (ISFET) in the 70's, through Micro-Electro-Mechanical-System (MEMS) sensors from the end of the 80's, chemical sensors are combining in the 90's MEMS technology with LSI intelligence to devise more selective, sensitive and autonomous devices to analyse complex mixtures. A brief history of chemical sensors from the ISFET to the nowadays LSI integrated sensors is first detailed. Then the states-of-the-art of LSI integrated chemical sensors and their wide range of applications are discussed. Finally the authors propose a brand-new usage of integrated wireless MEMS sensors for remote surveillance of chemical substances, such as food-industry or pharmaceutical products, that are stored in closed environment like a bottle, for a long period. In such environment, in-situ analyse is necessary, and electrical cables, for energy supply or data transfer, cannot be used. Thanks to integrated MEMS, an autonomous long-term in-situ quality deterioration tracking system is possible.

Liquid medium was investigated for creation of real 3D dynamic color images on a basis of laser breakdown effect experimentally. It was shown, that breakdown plasma flash in liquid can be used as a shining voxel of white color. Plasma flashing voxels were produced by means of YAG laser with repetition rate up to 2000 Hz of nanosecond mJ pulses. Breakdown bubbles were found to be not hampering the displaying by flashes. Tens of liquids were tested concerning the lowest breakdown threshold. Up to now, tap water was found to be an optimal medium for displaying due to its low breakdown threshold, low attenuation of laser beam and safety. Seeing through electronic driven color filter made a burst of voxels to be perceived like colored one. TFT matrix from LCD was successfully used for the test coloring. A kind of hysteresis was also found out for dependence of laser breakdown probability on laser repetition rate for fixed laser beam in tap water.

Recently the applications of MEMS (micro electro mechanical systems) have made remarkable progress in many filelds. The optical application of MEMS is one of the most promising because it provides micro mechano optical devices, the key components for high-perfromance systems in optical communication networks and data storage devices. This paper disucces the impacts of MEMS techologies on optical systems. Furthermore, state-of-the-art exmaples of micro optical switches, pig-tailed tunable filters and two-dimensional MEMS optical scanners are described.