scholarly journals Adding memory to pressure-sensitive phosphors

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Robin R. Petit ◽  
Simon E. Michels ◽  
Ang Feng ◽  
Philippe F. Smet
Keyword(s):  
Depth Distribution ◽  
Light Emission ◽  
Memory Function ◽  
Trap Depth ◽  
Mechanical Action ◽  
Stress Distributions ◽  
Pressure Sensing ◽  
Sensing Applications ◽  
Pressure Sensitive ◽  
Direct Light

Abstract Mechanoluminescence (ML) is the phenomenon describing the emission of light during mechanical action on a solid, leading to applications such as pressure sensing, damage detection and visualization of stress distributions. In most cases, this mechanical action releases energy that was previously stored in the crystal lattice of the phosphor by means of trapped charge carriers. A drawback is the need to record the ML emission during a pressure event. In this work, we provide a method for adding a memory function to these pressure-sensitive phosphors, allowing an optical readout of the location and intensity of a pressure event in excess of 72 h after the event. This is achieved in the BaSi2O2N2:Eu2+ phosphor, where a broad trap depth distribution essential for the process is present. By merging optically stimulated luminescence (OSL), thermoluminescence (TL) and ML measurements, the influence of light, heat and pressure on the trap depth distribution is carefully analysed. This analysis demonstrates that mechanical action can not only lead to direct light emission but also to a reshuffling of trap occupations. This memory effect not only is expected to lead to new pressure sensing applications but also offers an approach to study charge carrier transitions in energy storage phosphors.

PIEZORESISTIVE PROPERTIES OF MULTI-WALLED CARBON NANOTUBE–POLY(DIMETHYLSILOXANE) COMPOSITES FOR LOW-PRESSURE-SENSING APPLICATIONS

NANO ◽  
2012 ◽  
Vol 07 (01) ◽  
pp. 1250005 ◽  
Author(s):  
SU YONG KWON ◽  
YON KYU PARK ◽  
MIN SEOK KIM
Keyword(s):  
Conductive Filler ◽  
Low Pressure ◽  
Pressure Sensitivity ◽  
Pressure Sensing ◽  
Sensing Applications ◽  
Pressure Sensitive ◽  
Multi Walled Carbon Nanotube ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Mwcnt Loading

Low-pressure-sensitive composites using multi-walled carbon nanotubes as a conductive filler and poly(dimethylsiloxane) as a polymer matrix have been fabricated, and their electrical and piezoresistive properties have been studied. A large aspect ratio of the MWCNTs was used to achieve good electrical properties of the composite, which led to a significant decrease in the percolation threshold and an increase in the electrical conductivity for very low MWCNT loadings. The piezoresistive properties of the composites at < 1.2 MPa were studied, which showed that the resistance–pressure sensitivity of the composites could be modulated by varying the MWCNT loading in the PDMS matrix.

Fluorescent Nanotechnology: An Evolution in Optical Sensors

2020 ◽  
Vol 17 ◽  
Author(s):  
Dilawar Hassan ◽  
Hadi Bakhsh ◽  
Asif M. Khurram ◽  
Shakeel A. Bhutto ◽  
Nida S. Jalbani ◽  
...  
Keyword(s):  
Optical Properties ◽  
Optical Sensors ◽  
Light Emission ◽  
Environmental Contaminants ◽  
Fluorescent Nanoparticles ◽  
Sensing Applications ◽  
Properties Of Materials ◽  
Optical Properties Of Materials ◽  
Fluorescent Nanomaterials

Background: The optical properties of nanomaterials have evolved enormously with the introduction of nanotechnology. The property of materials to absorb and/or emit specific wavelength has turned them into one of the most favourite candidates to be effectively utilized in different sensing applications e.g organic light emission diodes (OLEDs) sensors, gas sensors, biosensors and fluorescent sensors. These materials have been reported as a sensor in the field of tissue and cell imaging, cancer detection and detection of environmental contaminants etc. Fluorescent nanomaterials are heling in rapid and timely detection of various contaminants that greatly impact the quality of life and food, that is exposed to these contaminants. Later, all the contaminants have been investigated to be most perilous entities that momentously affect the life span of the animals and humans who use those foods which have been contaminated. Objective: In this review, we will discuss about various methods and approaches to synthesize the fluorescent nanoparticles and quantum dots (QDs) and their applications in various fields. The application will include the detection of various environmental contaminants and bio-medical applications. We will discuss the possible mode of action of the nanoparticles when used as sensor for the environmental contaminants as well as the surface modification of some fluorescent nanomaterials with anti-body and enzyme for specific detection in animal kingdom. We will also describe some RAMAN based sensors as well as some optical sensing-based nanosensors. Conclusion: Nanotechnology has enabled to play with the size, shape and morphology of materials in the nanoscale. The physical, chemical and optical properties of materials change dramatically when they are reduced to nanoscale. The optical properties can become choosy in terms of emission or absorption of wavelength in the size range and can result in production of very sensitive optical sensor. The results show that the use of fluorescent nanomaterials for the sensing purposes are helping a great deal in the sensing field.

scholarly journals Predicting the afterglow duration in persistent phosphors: a validated approach to derive trap depth distributions

2018 ◽  
Vol 20 (48) ◽  
pp. 30455-30465 ◽  
Author(s):  
Olivier Q. De Clercq ◽  
Jiaren Du ◽  
Philippe F. Smet ◽  
Jonas J. Joos ◽  
Dirk Poelman
Keyword(s):  
Depth Distribution ◽  
Storage Capacity ◽  
Trap Depth ◽  
And Storage ◽  
Depth Distributions

The trap depth distribution of a persistent phosphor, obtained via thermoluminescence, is used to predict afterglow and storage capacity.

Carbon nanotube-based thermoplastic polyurethane-poly(methyl methacrylate) nanocomposites for pressure sensing applications

2016 ◽  
Vol 56 (9) ◽  
pp. 1031-1036 ◽  
Author(s):  
Syed Muhammad Imran ◽  
Godlisten N. Shao ◽  
M. Salman Haider ◽  
Hae Jin Hwang ◽  
Yong-Ho Choa ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Methyl Methacrylate ◽  
Thermoplastic Polyurethane ◽  
Pressure Sensing ◽  
Poly Methyl Methacrylate ◽  
Sensing Applications

Flexible hemispheric microarrays of highly pressure-sensitive sensors based on breath figure method

Nanoscale ◽  
2018 ◽  
Vol 10 (22) ◽  
pp. 10691-10698 ◽  
Author(s):  
Zhihui Wang ◽  
Ling Zhang ◽  
Jin Liu ◽  
Hao Jiang ◽  
Chunzhong Li
Keyword(s):  
Pressure Sensor ◽  
Pressure Sensors ◽  
Pressure Sensing ◽  
Sensing Range ◽  
Pressure Sensitive ◽  
Breath Figure ◽  
Breath Figure Method ◽  
Flexible Pressure Sensors

Flexible pressure sensors with interlocked hemispheric microstructures are prepared by a novel breath figure strategy. The subtle microstructure remarkably improves the sensitivity and pressure sensing range of the pressure sensor.

scholarly journals Subwavelength Silicon Nanoblocks for Directional Emission Manipulation

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1242
Author(s):  
Tianyue Zhang ◽  
Xuewei Li ◽  
Jian Xu ◽  
Xiaoming Zhang ◽  
Zi-Lan Deng ◽  
...  
Keyword(s):  
Light Emission ◽  
Coupled System ◽  
Low Loss ◽  
Preferential Direction ◽  
Nanophotonic Devices ◽  
Directional Emission ◽  
Direct Light ◽  
Highly Sensitive ◽  
Field Radiation ◽  
Magnetic Resonances

Manipulating the light emission direction and boosting its directivity have essential importance in integrated nanophotonic devices. Here, we theoretically propose a single dielectric silicon nanoblock as an efficient, multifunctional and ultracompact all-dielectric nanoantenna to direct light into a preferential direction. Unidirectional scattering of a plane wave as well as switchable directive emission fed by a localized emitter are demonstrated within the nanoantenna. The high directionalities are revealed to originate from a variety of mechanisms that can coexist within a single nanoblock, which contribute to the far-field radiation patterns of the outcoming light, thanks to the wealth of multipolar electric and magnetic resonances. The efficient beam redirections are also observed, which are sensitive to the local configurations of the emitter antenna coupled system. The designed antenna, with extreme geometry simplicity, ultracompact and low-loss features, could be favorable for highly sensitive sensing as well as applications in optical nanocircuits.

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