Humidity sensor based on a cross-linked porous polymer with unexpectedly good properties

RSC Advances ◽  
2014 ◽  
Vol 4 (41) ◽  
pp. 21429 ◽  
Author(s):  
Teng Fei ◽  
Kai Jiang ◽  
Sen Liu ◽  
Tong Zhang
Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1985 ◽  
Author(s):  
Maryam Mesgarpour Tousi ◽  
Yujing Zhang ◽  
Shaowei Wan ◽  
Li Yu ◽  
Chong Hou ◽  
...  

In this study, we fabricated a highly flexible fiber-based capacitive humidity sensor using a scalable convergence fiber drawing approach. The sensor’s sensing layer is made of porous polyetherimide (PEI) with its porosity produced in situ during fiber drawing, whereas its electrodes are made of copper wires. The porosity induces capillary condensation starting at a low relative humidity (RH) level (here, 70%), resulting in a significant increase in the response of the sensor at RH levels ranging from 70% to 80%. The proposed humidity sensor shows a good sensitivity of 0.39 pF/% RH in the range of 70%–80% RH, a maximum hysteresis of 9.08% RH at 70% RH, a small temperature dependence, and a good stability over a 48 h period. This work demonstrates the first fiber-based humidity sensor fabricated using convergence fiber drawing.


Author(s):  
Mukesh Mahajan ◽  
Astha Dubey ◽  
Samruddhi Desai ◽  
Kaveri Netawate

This paper reviews basically about Bluetooth based home automation system. It is controlled by PIC microcontroller. Home automation can be defined as the ability to perform tasks automatically and monitor or change status remotely. These include tasks such as turning off lights in the room, locking doors via smartphone, automate air condition systems and appliances which help in the kitchen. Now a days several wireless devices are available such as Bluetooth, Zigbee and GSM. Since Bluetooth is low in cost than the other two and hence is used more. In this paper we have described the methods of automating different home appliances using Bluetooth and pic microcontroller. Different sensors are involved in this system to advance and make it smarter. Sensors such as temperature sensor, liquid sensors, humidity sensor etc. can be used.


2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>


Author(s):  
Сергей Борисович Казаков ◽  
Дмитрий Михайлович Шишов ◽  
Антон Игоревич Ларин ◽  
Александр Петрович Николаев ◽  
Аза Валерьевна Писарева

В статье представлен обзор существующих технических решений в сфере мониторинга и предотвращения апноэ во сне. Произведён анализ существующих аппаратов для предотвращения апноэ, который показал, что на рынке присутствует большое количество импортных моделей, однако они имеют довольно высокую цену. Разработанный нами Российский аналог проектируемого аппарата, при схожих характеристиках, будет иметь более привлекательную цену, чем у импортных приборов. Интегрирование датчика влажности в персональную маску пациента даёт возможность отслеживать остановки дыхания пациента во время сна, и тем самым включать процесс принудительной подачи дыхательной смеси именно в тот момент, когда она необходима для устранения патологии. Целью научной работы является разработка конструкции прибора и создание алгоритма программы для управления аппарата искусственной вентиляции лёгких для предотвращения апноэ во сне. Показана разработка структуры устройства аппарата. Подобран компрессор и датчик влажности с обоснованными характеристиками для создания аппарата, а также основные элементы. Разработана конструкция корпуса аппарата и разработана компоновка. Выполнено технико-экономическое обоснование разработки аппаратно-программного комплекса для предотвращения апноэ во сне. Показано, что себестоимость готового изделия достаточно конкурентна The article presents an overview of existing technical solutions in the field of monitoring and prevention of sleep apnea. An analysis of existing devices for preventing apnea was made, which showed that there are a large number of imported models on the market, but they have a fairly high price. The Russian analog of the designed device developed by us, with similar characteristics, will have a more attractive price than that of imported devices. The integration of the humidity sensor into the patient's personal mask makes it possible to monitor the patient's breathing stops during sleep, and thus enable the process of forced delivery of the respiratory mixture at the exact moment when it is necessary to eliminate the pathology. The purpose of the research is to develop the device design and create a program algorithm for controlling the artificial lung ventilation device to prevent sleep apnea. The development of the device structure is shown. The compressor and humidity sensor with reasonable characteristics for creating the device, as well as the main elements are selected. The design of the device body and its layout were developed. A feasibility study for the development of a hardware and software system for preventing sleep apnea has been completed. It is shown that the cost of the finished product is quite competitive


2017 ◽  
Vol 53 (32) ◽  
pp. 4465-4468 ◽  
Author(s):  
Yuan Gao ◽  
Pengtao Jing ◽  
Ning Yan ◽  
Michiel Hilbers ◽  
Hong Zhang ◽  
...  

Combined photoluminescence and impedance spectroscopy studies show that a europium-based metal–organic framework behaves as a highly effective and reliable humidity sensor, enabling dual-mode humidity detection.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 648
Author(s):  
Aijie Liang ◽  
Jingyuan Ming ◽  
Wenguo Zhu ◽  
Heyuan Guan ◽  
Xinyang Han ◽  
...  

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.


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