Microfabrication of Thermoelectric Hydrogen Sensor Using KOH Solution Etching

2006 ◽  
Vol 301 ◽  
pp. 273-276 ◽  
Author(s):  
Kazuki Tajima ◽  
Yeong Soo Choi ◽  
Woosuck Shin ◽  
Noriya Izu ◽  
Ichiro Matsubara ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Hydrogen Oxidation ◽  
Exothermic Reaction ◽  
High Sensitivity ◽  
Response Speed ◽  
Hydrogen Sensor ◽  
Fast Response ◽  
Sensor Technology ◽  
Circuit Fabrication ◽  
Voltage Signal

Micromachined sensors are a new generation of sensor technology combining existing integrated circuit fabrication technology with novel deposition and etching processing. In the viewpoint of low-power operation, high sensitivity and fast response speed of thermoelectric hydrogen sensor (THS), we prepared the micromachined thermoelectric hydrogen sensor (micro-THS) with the combination of the thermoelectric effect of SiGe thin film and the Pt-catalyzed exothermic reaction of hydrogen oxidation. The power consumption of the micro-THS was greatly reduced to be 50 mW for 100 °C operating, by the Pt-micro-heater on single membrane. The micro-THS with 40 wt.% Pt/alumina catalyst showed voltage signal of 10 mV for 1 % H2 in air.

B- and P-Doped Si0.8Ge0.2 Thin Film Deposited by Helicon Sputtering for the Micro-Thermoelectric Gas Sensor

2006 ◽  
Vol 320 ◽  
pp. 99-102 ◽  
Author(s):  
Kazuki Tajima ◽  
Woosuck Shin ◽  
Maiko Nishibori ◽  
Norimitsu Murayama ◽  
Toshio Itoh ◽  
...  
Keyword(s):  
Thin Film ◽  
Hydrogen Oxidation ◽  
Exothermic Reaction ◽  
High Sensitivity ◽  
Hydrogen Sensor ◽  
Thermoelectric Effect ◽  
Boron Doped ◽  
Reliable Monitoring ◽  
Ppm Level ◽  
Pt Catalyzed

Micro-thermoelectric hydrogen sensor (micro-THS) with the combination of the thermoelectric effect of Si0.8Ge0.2 thin film and the Pt-catalyzed exothermic reaction of hydrogen oxidation was prepared by microfabrication process. In the viewpoint of high sensitivity of micro-THS, the thermoelectric properties of the Si0.8Ge0.2 thin film could be improved by optimizing carrier concentration using helicon sputtering with an advantage of easy doping control, and sensitivity of the device with this thin film was investigated. As the result, the boron-doped Si0.8Ge0.2 thin film is considered to be the better choice ensuring the reliable monitoring of hydrogen concentration down to ppm level.

scholarly journals Tin Disulfide-Coated Microfiber for Humidity Sensing with Fast Response and High Sensitivity

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  
Keyword(s):  
Humidity Sensor ◽  
Small Diameter ◽  
High Sensitivity ◽  
Large Change ◽  
Small Variation ◽  
Response Speed ◽  
Fast Response ◽  
Tin Disulfide ◽  
Recovery Times ◽  
Response And Recovery

Breath monitoring is significant in assessing human body conditions, such as cardiac and pulmonary symptoms. Optical fiber-based sensors have attracted much attention since they are immune to electromagnetic radiation, thus are safe for patients. Here, a microfiber (MF) humidity sensor is fabricated by coating tin disulfide (SnS2) nanosheets onto the surface of MF. The small diameter (~8 μm) and the long length (~5 mm) of the MF promise strong interaction between guiding light and SnS2. Thus, a small variation in the relative humidity (RH) will lead to a large change in optical transmitted power. A high RH sensitivity of 0.57 dB/%RH is therefore achieved. The response and recovery times are estimated to be 0.08 and 0.28 s, respectively. The high sensitivity and fast response speed enable our SnS2-MF sensor to monitor human breath in real time.

Micro Hydrogen Gas Sensor Based on Bi-Te Film Couples and Pt/ACC

2007 ◽  
Author(s):  
Hu Huang ◽  
Jian-Song Zhang ◽  
Weiling Luan ◽  
Shan-Tung Tu ◽  
Shang-Kuo Yang
Keyword(s):  
Gas Sensor ◽  
Hydrogen Oxidation ◽  
Exothermic Reaction ◽  
High Sensitivity ◽  
Clean Energy ◽  
Rf Magnetron Sputtering ◽  
Energy System ◽  
Hydrogen Gas ◽  
Activated Carbon Fiber ◽  
Thin Glass

TE (Thermoelectric) materials have been widely used in clean energy system as low-power generator and Peliter cooler, due to its salient features of being compact, light-weighted, noiseless in operation, highly reliable, and environment friendly. Recently, another application has been explored on TE materials as gas sensors based on Seebeck effect and exothermic reaction of hydrogen oxidation on catalyst. In this paper, a TE hydrogen gas sensor with a simple structure, low energy consumption and a high sensitivity was reported. Bi-Te (bismuth telluride) with a high Seebeck coefficient at room-temperature was deposited onto thin glass substrates by RF magnetron sputtering technology. Four pairs of PN film couples were connected in series to improve the output voltage. Pt/ ACC (Activated Carbon Fiber Cloth) was mounted at the joint of PN couples, acting as catalyst so as to accelerate the oxidation of hydrogen. The influences of reduction temperature and Pt content on the generated temperature difference were investigated. The voltage output and selectivity to combustible gas mixture were measured. Experimental results showed that when exposed to 3vol% H2/ air, as-prepared sensor gave out a high output signal of 33.1mV, and the response time was about 50s with recovery time of 50s.

scholarly journals Development of a High Stability Pd-Ni Alloy Thin-Film Coated SAW Device for Sensing Hydrogen

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3560 ◽  
Author(s):  
Wen Wang ◽  
Xueli Liu ◽  
Shengchao Mei ◽  
Mengwei Liu ◽  
Chao Lu ◽  
...  
Keyword(s):  
Thin Film ◽  
High Sensitivity ◽  
Hydrogen Sensor ◽  
Fast Response ◽  
Propagation Path ◽  
Alloy Thin Film ◽  
Optimal Parameters ◽  
Ni Alloy ◽  
Oscillation Loop ◽  
Coated Surface

A Pd-Ni alloy thin-film coated surface acoustic wave (SAW) device is proposed for sensing hydrogen. The Pd-Ni thin-film was sputtered onto the SAW propagation path of a SAW device with a delay line pattern to build the chip-sized hydrogen sensor. The prepared sensor chip was characterized by employing a differential oscillation loop. The effect of the Pd-Ni film thickness on sensing performance was also evaluated, and optimal parameters were determined, allowing for fast response and high sensitivity. Excellent working stability (detection error of 3.7% in half a year), high sensitivity (21.3 kHz/%), and fast response (less than 10 s) were achieved from the 40 nm Pd-Ni alloy thin-film coated sensing device.

scholarly journals Inch-sized high-quality perovskite single crystals by suppressing phase segregation for light-powered integrated circuits

2021 ◽  
Vol 7 (7) ◽  
pp. eabc8844
Author(s):  
Yucheng Liu ◽  
Yunxia Zhang ◽  
Xuejie Zhu ◽  
Zhou Yang ◽  
Weijun Ke ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Single Crystals ◽  
Integrated Circuit ◽  
High Performance ◽  
Imaging System ◽  
Phase Segregation ◽  
Response Speed ◽  
Fast Response ◽  
High Quality ◽  
Carrier Lifetimes

The triple-cation mixed-halide perovskite (FAxMAyCs1-x-y)Pb(IzBr1-z)3 (FAMACs) is the best composition for thin-film solar cells. Unfortunately, there is no effective method to prepare large single crystals (SCs) for more advanced applications. Here, we report an effective additive strategy to grow 2-inch-sized high-quality FAMACs SCs. It is found that the judiciously selected reductant [formic acid (FAH)] effectively minimizes iodide oxidation and cation deprotonation responsible for phase segregation. Consequently, the FAMACs SC shows more than fivefold enhancement in carrier lifetimes, high charge mobility, long carrier diffusion distance, as well as superior uniformity and long-term stability, making it possible for us to design high-performance self-powered integrated circuit photodetector. The device exhibits large responsivity, high photoconductive gain, excellent detectivity, and fast response speed; all values are among the highest reported to date for planar-type single-crystalline perovskite photodetectors. Furthermore, an integrated imaging system is fabricated on the basis of 12 × 12 pixelated matrixes of the single-crystal photodetectors.

High-sensitivity and fast-response fiber-tip Fabry–Pérot hydrogen sensor with suspended palladium-decorated graphene

Nanoscale ◽  
2019 ◽  
Vol 11 (34) ◽  
pp. 15821-15827 ◽  
Author(s):  
Jun Ma ◽  
Yanglin Zhou ◽  
Xue Bai ◽  
Kai Chen ◽  
Bai-Ou Guan
Keyword(s):  
Fiber Optic ◽  
High Sensitivity ◽  
Hydrogen Sensor ◽  
Fast Response ◽  
Hydrogen Detection ◽  
Sensing Technology ◽  
Fabry Perot ◽  
Fiber Optic Sensing

Integration of suspended Pd-decorated graphene and fiber-optic sensing technology enables sensitive, fast-response, and intrinsically safe hydrogen detection.

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