This paper presents a new type of ultrasonic gas molecule concentration sensor for rescue robotics and the performance of developed sensor is investigated by applying as human breath gas measurement sensor. This devise can measure the change of the gas concentration with a sampling rate of 400 kHz. Ideal gas experiment results show that the proposed sensor could detect the difference between 5%...

A gas sensor, comprised of a gas-responsive multiwall carbon nanotube (MWNT)—silicon dioxide (SiO2) composite layer deposited on a planar inductor-capacitor resonant circuit is presented here for the monitoring of carbon dioxide (CO2), oxygen (O2), and ammonia (NH3). The absorption of different gases in the MWNT-SiO2 layer changes the permittivity and conductivity of the material and consequent...

Microstructured single- and double-layered sensor devices based on p-type hydrogen-terminated nanocrystalline diamond (NCD) films and/or n-type ZnO nanorods (NRs) have been obtained via a facile microwave-plasma-enhanced chemical vapour deposition process or a hydrothermal growth procedure. The morphology and crystal structure of the synthesized materials was analysed with scanning electron mic...

A study about the piezoresistive Micro-Electro-Mechanical Systems (MEMS) cantilever for a chemical sensitive mass based sensor has been carried out to enhance sensor sensitivity. The sensitive region attracts the CO2 molecules there by introducing the stress concentration region (SCR). Three types of SCR geometry designs were first analysed using Intellisuite software to study the effect of str...

A study about the piezoresistive Micro-Electro-Mechanical Systems (MEMS) cantilever for a chemical sensitive mass based sensor has been carried out to enhance sensor sensitivity. The sensitive region attracts the CO2 molecules there by introducing the stress concentration region (SCR). Three types of SCR geometry designs were first analysed using Intellisuite software to study the effect of str...

A novel handheld side-stream breath analyser has been developed. The low-cost device offers breath-by-breath measurements of O2, CO2, temperature, relative humidity and gas flow rate. Metabolic rate can be calculated from the inspired and expired gas concentrations; a knowledge of this over a 24 h period can guide calorific intake. The analyser provides easy-to-read results on either a laptop o...

We report a light, flexible, and low-power poly(ionic liquid)/alumina composite CO2 sensor. We monitor the direct-current resistance changes as a function of CO2 concentration and relative humidity and demonstrate fast and reversible sensing kinetics. Moreover, on the basis of the alternating-current impedance measurements we propose a sensing mechanism related to proton conduction and gas diff...

Gastroenterologists are still unable to differentiate between some of the most ordinary disorders of the gut and consequently patients are misdiagnosed. We have developed a swallowable gas sensor capsule for addressing this. The gases of the gut are the by-product of the fermentation processes during digestion, affected by the gut state and can consequently provide the needed information regard...

A Kalman filtering technique is applied to the simultaneous detection of NH3 and CO2 with a diode-laser-based sensor operating at 1.53 micrometers. This technique is developed for improving the sensitivity and precision of trace gas concentration levels based on direct overtone laser absorption spectroscopy in the presence of various sensor noise sources. Filter performance is demonstrated to b...