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The use of thin films as sensing elements for microsensor applications has been shown very attractive due to their low-cost fabrication, potential for integration with standard CMOS technologies and possibility of deposition on different substrate types. In particular, piezoresistive sensors based on thin films have been commonly developed because can be easily implemented using microfabrication processes and present the best relation between sensitivity and system complexity, which showing great advantages in term of device integration. In our previous works (Fraga et al. 2010(Fraga et al. , 2011a, we studied undoped and nitrogen-doped PECVD a-SiC thin films as alternative materials to replace the silicon piezoresistors in strain and pressure sensors for harsh environments. Here, we focused our attention on the piezoresistive properties of sputtered silicon carbide (SiC), diamond-like carbon (DLC) and titanium dioxide (TiO 2 ) thin films. These materials were evaluated in terms of sensitivity or gauge factor and of the influence of the temperature on this sensitivity, allowing a preliminary analysis of the applicability of these thin films in high temperature piezoresistive sensors.

Highly sensitive protein characterisation on a new label-free biosensor system is reported. The system consists of a VCSEL, a plastic guided mode resonant filter and two pin detectors. It is suitable for measuring both static and dynamic interaction among proteins and can detect an antigen concentration as low as 1 pg=ml (6.7 femtoMolar).

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We have designed and fabricated a subwavelength grating ͑SWG͒ broadband mirror whose performance depends on key factors, including SWG period, duty cycle, and angle of incident light. The fabricated SWGs exhibit high reflectivity ͑ജ96% ͒, when the grating periods are varied from 650 to 750 nm and duty cycles are varied from 55% to 65%. The bandwidth and reflectivity of these mirrors are remarkably robust to variations in design and fabrication. The SWGs can be designed as broadband mirrors from microwave to visible wavelengths.

In order to evaluate the potential of amorphous silicon carbide (a-SiC) films for piezoresistive sensors applications, a pressure sensor has been developed based on this material. The deposition conditions and properties of a-SiC films deposited on thermally oxidized (100) Si substrates by two techniques enhanced by plasma, PECVD (plasma enhanced chemical vapor deposition) and RF magnetron sputtering, are briefly described and compared. Among the SiC films produced, we choose the nitrogendoped PECVD SiC film to fabricate the piezoresistors of the sensor. The structure of the sensor consists of six a-SiC piezoresistors, configured in Wheatstone bridge, on a SiO 2 / Si square diaphragm. The sensor was tested for applied pressure ranging from 0 to 12 psi and supply voltage of 12 V. A preliminary study of the influence of the temperature on the performance of the sensor was performed by experimental measurements and theoretical investigations.