Hydrogen sensors are of increasing importance in connection with the development and expanded use of hydrogen gas as an energy carrier and as a chemical reactant. There are an immense number of sensors reported in the literature for hydrogen detection and in this work these sensors are classified into eight different operating principles. Characteristic performance parameters of these sensor types, such as measuring range, sensitivity, selectivity and response time are reviewed and the latest technology developments are reported. Testing and validation of sensor performance are described in relation to standardisation and use in potentially explosive atmospheres so as to identify the requirements on hydrogen sensors for practical applications.

Hydrogen Sensors - A review

Metal oxide semiconductor gas sensors are utilised in a variety of different roles and industries. They are relatively inexpensive compared to other sensing technologies, robust, lightweight, long lasting and benefit from high material sensitivity and quick response times. They have been used extensively to measure and monitor trace amounts of environmentally important gases such as carbon monoxide and nitrogen dioxide. In this review the nature of the gas response and how it is fundamentally linked to surface structure is explored. Synthetic routes to metal oxide semiconductor gas sensors are also discussed and related to their affect on surface structure. An overview of important contributions and recent advances are discussed for the use of metal oxide semiconductor sensors for the detection of a variety of gases—CO, NOx, NH3 and the particularly challenging case of CO2. Finally a description of recent advances in work completed at University College London is presented including the use of selective zeolites layers, new perovskite type materials and an innovative chemical vapour deposition approach to film deposition.

https://www.mdpi.com/1424-8220/10/6/5469/pdf

Metal Oxide Semi-Conductor Gas Sensors in Environmental Monitoring

The theoretical and experimental issues relevant to neutrinoless double beta decay are reviewed. The impact that a direct observation of this exotic process would have on elementary particle physics, nuclear physics, astrophysics, and cosmology is profound. Now that neutrinos are known to have mass and experiments are becoming more sensitive, even the nonobservation of neutrinoless double beta decay will be useful. If the process is actually observed, we will immediately learn much about the neutrino. The status and discovery potential of proposed experiments are reviewed in this context, with significant emphasis on proposals favored by recent panel reviews. The importance of and challenges in the calculation of nuclear matrix elements that govern the decay are considered in detail. The increasing sensitivity of experiments and improvements in nuclear theory make the future exciting for this field at the interface of nuclear and particle physics.

/pdf/double-beta-decay-majorana-neutrinos-and-neutrino-mass-2tfhqvhys8.pdf

Double Beta Decay, Majorana Neutrinos, and Neutrino Mass

An apparatus may include a semiconductor chip and a fluidics assembly. The semiconductor chip has an array of wells and an array of sensors and each sensor of the array of sensors is in fluid communication with a well of the array of wells. The fluidics assembly is located on top of the semiconductor chip and is configured to deliver fluids to the semiconductor chip. The fluidics assembly includes a flow expansion chamber configured to introduce the fluids, an outlet portion configured to pipe out the fluids, and a flow chamber portion. The flow chamber portion is configured to allow the fluids to flow from the flow expansion chamber to the outlet portion and to allow the fluids to interact along the way with material in the array of wells. The flow expansion chamber has a curved wall at the top or bottom so that the height of the flow expansion chamber at the center is less than at the walls that restrict the fluids to the left and right.

Methods and apparatus for measuring analytes using large scale fet arrays

Methods and apparatus relating to FET arrays including large FET arrays for monitoring chemical and/or biological reactions such as nucleic acid sequencing-by-synthesis reactions. Some methods provided herein relate to improving signal (and also signal to noise ratio) from released hydrogen ions during nucleic acid sequencing reactions.

Methods and apparatus for measuring analytes

Microstructures etched in doped TMAH solutions

Low-power thick-film gas sensor obtained by a combination of screen printing and micromachining techniques

In this work we present a reconfigurable mid-power Class-E Power Amplifier (PA) [1,2] operating at ~900MHz and ~1800MHz (GSM standard [3]) realized hybridizing one chip manufactured in AMS 0.35 ?m CMOS technology and one MEMS sub-network. The CMOS chip realizes the active part of the circuit, whereas the MEMS block (realized in FBK technology) implements a reconfigurable impedance Matching Network (MN) that transforms the 50? antenna load to the 12? impedance required by the PA in order to deliver 20dBm output power in both the GSM operating frequency bands. The prototype of the MEMS/CMOS PA we realized delivers 20dBm with 38% and 26% drain efficiencies at 900MHz and 1800MHz, respectively, demonstrating to be a feasible option compared to standard commercial solutions.

A MEMS Reconfigurable Quad-Band Class-E Power Amplifier for GSM Standard

Experimental results obtained for a binary distributed phase shifter based on RF MEMS coplanar shunt switches are presented A new approach based on the image parameter representation of two-port networks is proposed for the modelling of this structure Vector network analyser measurements have been performed by recording the scattering parameters of the device, obtaining a differential phase shift of 180° at a frequency f0 = 137 GHz, very close to the theoretical one ftheo=14 GHz A very low number of switches has been used for the realisation of the component

Benno Margesin

Papers

Microstructures etched in doped TMAH solutions

Low-power thick-film gas sensor obtained by a combination of screen printing and micromachining techniques

A MEMS Reconfigurable Quad-Band Class-E Power Amplifier for GSM Standard

Realisation of distributed RF MEMS phase shifter with very low number of switches

Electromechanical characterization of low actuation voltage RF MEMS capacitive switches based on DC CV measurements