Monitoring acidic and basic volatile concentration using a pH-electrode based wireless passive sensor

Bhadra, Sharmistha; Thomson, D. J.; Bridges, Greg E.

doi:10.1016/j.snb.2014.12.021

Cited by 37 publications

(9 citation statements)

References 32 publications

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“…Depending on the transduction principle, the capacitance, inductance or resistance of the LC sensing circuit is affected by the measurand, allowing both physical and chemical sensors. Therefore, various kinds of passive wireless LC sensors have been developed to measure parameters inside sealed or harsh environments [2]- [6], e.g., pressure inside the human body [7]- [9], electrocardiogram [8], high temperatures in internal combustion engines [10], quality of packaged food [11] [12], water content in building materials [13], pH control [14], temperature [6], [15], [16], and relative humidity [17]- [21], among others.…”

Section: Introductionmentioning

confidence: 99%

Readout Circuit With Improved Sensitivity for Contactless LC Sensing Tags

et al. 2020

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In this work we present a novel technique to estimate the resonance frequency of LC chipless tags (inductorcapacitor parallel circuit) with improved sensitivity and linearity. The developed reader measures the power consumption of a Colpitts oscillator during a frequency sweep. The readout circuit consists of a Colpitts oscillator with a coil antenna, varactor diodes to change the oscillator frequency, analog circuitry to measure the power consumption and a microcontroller to control the whole system and send the data to a PC via USB. When an LC tag is inductively coupled to the oscillator, without contact, a maximum power peak is found. As shown by an experimental calibration using an LC tag made on FR4 substrate, the frequency of this maximum is related to the resonance frequency. Both parameters, power consumption and resonance frequency, present an excellent linear dependence with a high correlation factor (R 2 = 0.995). Finally, a screen-printed LC tag has been fabricated and used as relative humidity sensor achieving a sensitivity of (-2.41 ± 0.21) kHz/% with an R 2 of 0.946.

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Section: Introductionmentioning

confidence: 99%

Readout Circuit With Improved Sensitivity for Contactless LC Sensing Tags

et al. 2020

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“…On one hand, some authors have associated the tag’s analog response (read range, resonance frequency, backscattered power, etc.) with a variation in the monitored magnitude [ 4 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. However, although quite valuable results have been achieved, several factors could interfere in link performance, making it difficult to distinguish whether the change in the tag’s analog response is in fact due to a variation in magnitude or to some other interference.…”

Section: Introductionmentioning

confidence: 99%

Passive UHF RFID Tag for Multispectral Assessment

Escobedo

Carvajal

Capitán-Vallvey

et al. 2016

Sensors

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This work presents the design, fabrication, and characterization of a passive printed radiofrequency identification tag in the ultra-high-frequency band with multiple optical sensing capabilities. This tag includes five photodiodes to cover a wide spectral range from near-infrared to visible and ultraviolet spectral regions. The tag antenna and circuit connections have been screen-printed on a flexible polymeric substrate. An ultra-low-power microcontroller-based switch has been included to measure the five magnitudes issuing from the optical sensors, providing a spectral fingerprint of the incident electromagnetic radiation from ultraviolet to infrared, without requiring energy from a battery. The normalization procedure has been designed applying illuminants, and the entire system was tested by measuring cards from a colour chart and sensing fruit ripening.

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“…Rapidly increasing numbers of wireless sensor nodes and their networks (WSNs), ranging in applications of structural health (e.g., cracks in buildings), industrial environments (e.g., machining processes), household/weather conditions (e.g., temperature and humidity) and even human health and well-being monitoring have kept energy harvesting as a target of researchers for many years [ 8 , 9 , 10 ].…”

Section: Introductionmentioning

confidence: 99%

Peculiarities of the Third Natural Frequency Vibrations of a Cantilever for the Improvement of Energy Harvesting

Ostaševičius

Janušas

Milasauskaite

et al. 2015

Sensors

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This paper focuses on several aspects extending the dynamical efficiency of a cantilever beam vibrating in the third mode. A few ways of producing this mode stimulation, namely vibro-impact or forced excitation, as well as its application for energy harvesting devices are proposed. The paper presents numerical and experimental analyses of novel structural dynamics effects along with an optimal configuration of the cantilever beam. The peculiarities of a cantilever beam vibrating in the third mode are related to the significant increase of the level of deformations capable of extracting significant additional amounts of energy compared to the conventional harvester vibrating in the first mode. Two types of a piezoelectric vibrating energy harvester (PVEH) prototype are analysed in this paper: the first one without electrode segmentation, while the second is segmented using electrode segmentation at the strain nodes of the third vibration mode to achieve effective operation at the third resonant frequency. The results of this research revealed that the voltage generated by any segment of the segmented PVEH prototype excited at the third resonant frequency demonstrated a 3.4–4.8-fold increase in comparison with the non-segmented prototype. Simultaneously, the efficiency of the energy harvester prototype also increased at lower resonant frequencies from 16% to 90%. The insights presented in the paper may serve for the development and fabrication of advanced piezoelectric energy harvesters which would be able to generate a considerably increased amount of electrical energy independently of the frequency of kinematical excitation.

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Monitoring acidic and basic volatile concentration using a pH-electrode based wireless passive sensor

Cited by 37 publications

References 32 publications

Readout Circuit With Improved Sensitivity for Contactless LC Sensing Tags

Readout Circuit With Improved Sensitivity for Contactless LC Sensing Tags

Passive UHF RFID Tag for Multispectral Assessment

Peculiarities of the Third Natural Frequency Vibrations of a Cantilever for the Improvement of Energy Harvesting

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