Nanoelectromechanical systems (NEMS) have been proven to be ultrasensitive sensors for a variety of physical variables with unprecedented sensitivity, including force, mass, electrical charge, magnetic field, pressure, and heat. This thesis is intended to discuss using NEMS devices as chemical gas sensors, in a portable and compact total chemical analysis system. An integrated transduction meth...

Dozens of small dual-beam thin-film temperature sensors with a total width down to 430 nm were fabricated and tested. The sensors were all made from 90-nm-thick Pd thin films, where the width of the narrow stripes was 70-100 nm and that of the wide ones was 210-800 nm. Two different calibration methods showed consistent and repeatable sensitivities of 0.7-1.2 μV/K for the sensors, confirming th...

Nanocrystalline semiconducting thin films of copper sulphide (Cu2S) were deposited by novel chemical route using aqueous solution of 0.1 M copper chloride, 0.05 M thiourea, complexing agent 10% aqueous ammonia (NH3) and hydrazine hydrate. The characterization and gas sensitivity of as deposited Cu2S thin film sensor have been investigated. The as deposited Cu2S thin films were observed to be ve...

Polymeric composite films with a high loading of nano-size silicates can hardly meet the increasingly stringent fireproof and smoke-free requirements during burning. Thus, it is desirable to prepare pure clay films that can block air, heat, and flame. Here we report an organic-free clay film capable of both flame- and heat-shielding. The film was prepared from the self-assembly of nanometer-thi...

The paper presents general information on LTCC materials, manufacturing processes and properties of fired modules. A Multichip Module package has been the main application of Low Temperature Cofired Ceramic (LTCC) technology. Recently, this technology is also used for production of sensors, actuators and microsystems. The research and development on the LTCC sensors and microsystems carried out...

We report a novel route for enhancing the humidity resistance of SnO2 nanowires (NWs; widely used metal oxide semiconductor gas sensors) based on their coating with humidity-resistant nanomembrane. A conformal thin film was deposited by Molecular Layer Deposition (MLD) NWs using trimethylaluminum and ethylene glycol as precursors (100 MLD cycles), followed oxidation in air at 400 °C. In conditi...

In this review we discuss the advances in use of GaN and ZnO-based solid-state sensors for gas sensing applications. AlGaN/GaN high electron mobility transistors (HEMTs) show a strong dependence of source/drain current on the piezoelectric polarization -induced two dimensional electron gas (2DEG). Furthermore, spontaneous and piezoelectric polarization induced surface and interface charges can ...

This paper reports a micromachined chemical sensor intended for harsh environments such as those near hydrothermal vents at the sea floor. The sensor is intended to measure the pH, dissolved H2 and H2S, and temperature. The device is 12 mm in diameter and 6 mm in effective length, including packaging. A YSZ|HgO|Hg solid electrode is used as a common electrode for measurement of the three chemic...

Integrated particle sensors have been developed using thin-film on ASIC technology. For this purpose, hydrogenated amorphous silicon diodes, in various configurations, have been optimized for particle detection. These devices were first deposited on glass substrates to optimize the material properties and the dark current of very thick diodes (with thickness up to 50 μm). Corresponding diodes w...

Metal oxide gas sensors are predominant solid-state gas detecting devices for domestic, commercial and industrial applications, which have many advantages such as low cost, easy production, and compact size. However, the performance of such sensors is significantly influenced by the morphology and structure of sensing materials, resulting in a great obstacle for gas sensors based on bulk materi...