scholarly journals Design of Miniaturized, Self-Out-Readable Cantilever Resonator for Highly Sensitive Airborne Nanoparticle Detection

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 879
Author(s):  
Maik Bertke ◽  
Jiushuai Xu ◽  
Michael Fahrbach ◽  
Andi Setiono ◽  
Gerry Hamdana ◽  
...  
Keyword(s):  
Rest Mass ◽  
Particle Separation ◽  
Optimized Design ◽  
Nanoparticle Detection ◽  
Highly Sensitive ◽  
Measurement Signal ◽  
Monitoring Devices ◽  
Theoretical Sensitivity ◽  
Maximum Measurement ◽  
Airborne Nanoparticle

In this paper, a self-out-readable, miniaturized cantilever resonator for highly sensitiveairborne nanoparticle (NP) detection is presented. The cantilever, which is operated in thefundamental in-plane resonance mode, is used as a microbalance with femtogram resolution. Toachieve a maximum measurement signal of the piezo resistive Wheatstone half-bridge, thegeometric parameters of the sensor design were optimized by finite element modelling (FEM).Struts at the sides of the cantilever resonator act as piezo resistors and enable an electrical read-outof the phase information of the cantilever movement whereby they do not contribute to theresonators rest mass. For the optimized design, a resonator mass of 0.93 ng, a resonance frequencyof ~440 kHz, and thus a theoretical sensitivity of 4.23 fg/Hz can be achieved. A μ-channel guiding aparticle-laden air flow towards the cantilever is integrated into the sensor chip. Electrically chargedNPs will be collected by an electrostatic field between the cantilever and a counter-electrode at theedges of the μ-channel. Such μ-channels will also be used to accomplish particle separation for sizeselectiveNP detection. Throughout, the presented airborne NP sensor is expected to demonstratesignificant improvements in the field of handheld, MEMS-based NP monitoring devices.

scholarly journals Strategy toward Miniaturized, Self-out-Readable Resonant Cantilever and Integrated Electrostatic Microchannel Separator for Highly Sensitive Airborne Nanoparticle Detection

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 901 ◽  
Author(s):  
Maik Bertke ◽  
Jiushuai Xu ◽  
Michael Fahrbach ◽  
Andi Setiono ◽  
Hutomo Wasisto ◽  
...  
Keyword(s):  
Particle Separation ◽  
Signal Amplitude ◽  
Resonance Mode ◽  
Nanoelectromechanical Systems ◽  
Nanoparticle Detection ◽  
Highly Sensitive ◽  
Real Time Tracking ◽  
Monitoring Devices ◽  
Theoretical Sensitivity ◽  
Airborne Nanoparticle

In this paper, a self-out-readable, miniaturized cantilever resonator for highly sensitive airborne nanoparticle (NP) detection is presented. The cantilever, which is operated in the fundamental in-plane resonance mode, is used as a microbalance with femtogram resolution. To maximize sensitivity and read-out signal amplitude of the piezo-resistive Wheatstone half bridge, the geometric parameters of the sensor design are optimized by finite element modelling (FEM). The electrical read-out of the cantilever movement is realized by piezo-resistive struts at the sides of the cantilever resonator that enable real-time tracking using a phase-locked loop (PLL) circuit. Cantilevers with minimum resonator mass of 1.72 ng and resonance frequency of ~440 kHz were fabricated, providing a theoretical sensitivity of 7.8 fg/Hz. In addition, for electrostatic NP collection, the cantilever has a negative-biased electrode located at its free end. Moreover, the counter-electrode surrounding the cantilever and a µ-channel, guiding the particle-laden air flow towards the cantilever, are integrated with the sensor chip. µ-channels and varying sampling voltages will also be used to accomplish particle separation for size-selective NP detection. To sum up, the presented airborne NP sensor is expected to demonstrate significant improvements in the field of handheld, micro-/nanoelectromechanical systems (M/NEMS)-based NP monitoring devices.

scholarly journals Self-reading femtogram microbalance for highly sensitive airborne nanoparticle detection

2019 ◽  
Vol 1319 ◽  
pp. 012004
Author(s):  
M Bertke ◽  
J Xu ◽  
A Setiono ◽  
G Hamdana ◽  
H S Wasisto ◽  
...  
Keyword(s):  
Nanoparticle Detection ◽  
Highly Sensitive ◽  
Airborne Nanoparticle

Optimal Design of Electrode Structure and Microfluidics Channel for Effective Particle Separations

2013 ◽  
Author(s):  
Yun Chen ◽  
Souran Manoochehri
Keyword(s):  
Optimal Design ◽  
Electric Field ◽  
Particle Separation ◽  
Simulation Software ◽  
Optimized Design ◽  
Electrode Arrays ◽  
Electrode Structure ◽  
Effective Particle ◽  
Particle Separations ◽  
Microfluidics Channel

This paper presents the optimal design of electrode structure and microfluidics channel for effective particle separations. The purpose of the microfluidics chip is to generate the DEP (dielectrophoresis) force within the micro channel to separate both negative DEP (nDEP) and positive DEP (pDEP) particles of same sizes. The particles will experience DEP force when passing through the electric field created by electrode arrays located in different positions within the channel. The channel contains several electrode arrays where the pDEP particles are moved away from the electrodes and the nDEP particles are attracted towards them. In some existing microfluidics chips, because of the high intensity of the electric field around the electrodes, which results in a very high DEP force near the electrodes, most of the positive DEP particles are captured in the space between electrodes without being guided to the target outlet. Moreover, the effective area of DEP force is limited to a small region near the corner of the electrodes, therefore only those particles very close to the electrodes will experience sufficient attractive forces to be guided towards the target locations. This will decrease the efficiency of the particle separation. In this study, we developed an optimization methodology for design of electrode configurations using numerical modeling. The optimized electrode structure can provide much more evenly distributed DEP field. The design of the channel, the number and position of the electrode arrays were optimized in order to improve the efficiency of the particle separation. Finally, the optimized electrode structure and microfluidics channel were modeled and tested using multiphysics simulation software and the results show that this optimized design of microfluidics channel can provide high throughput and more effectiveness for particle separation compared to many existing microfluidics devices.

Cyclone pressure drop reduction and its effect on gas–particle separation capability: principle, performance, and assessment

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bingtao Zhao ◽  
Weifeng Qian ◽  
Huimei Li ◽  
Yaxin Su
Keyword(s):  
Pressure Drop ◽  
Chemical Engineering ◽  
Euler Number ◽  
Particle Separation ◽  
Stokes Number ◽  
Optimized Design ◽  
Key Issues ◽  
Technical Principles ◽  
Separation Performances ◽  
Insight Into

Abstract Cyclone separators have been widely used for gas–particle separation in chemical engineering. However, their enhancement in separation performances usually increases the pressure drop, which inevitably leads to an increase in operating energy consumption. One of the challenging issues is how to reduce the cyclone pressure drop while improving separation performances. To gain insight into the pathways and impacts of cyclone pressure drop reduction, this work reviews the state-of-the-art technical principles, performances and effects, focusing on the processes, mechanisms, and characteristics of pressure drop reduction by inlet/outlet variations, additional auxiliary devices, local cyclone dimension improvement, and global optimization based on intelligent algorithms. The cyclone performances are assessed using a proposed index that combines the Euler number and the square-root particle cut-off Stokes number. It is suggested that the pressure drop and separation capability usually have a dynamic compromise. Considering the comprehensive performances, the technology using helical roof inlet, cross cone, increasing cylindrical height with h/D = 4.3 (H/D = 6.35), and globally optimized design by Sun et al. (2017) are respectively considered to the others. Particularly, the last one is recommended to be more representative in practice. Finally, the key issues to be considered in further research were also prospected.

scholarly journals Nitrogen Dioxide Selective Sensor for Humid Environments Based on Octahedral Indium Oxide

2021 ◽  
Vol 2 ◽  
Author(s):  
Guillem Domènech-Gil ◽  
Isabel Gràcia ◽  
Carles Cané ◽  
Albert Romano-Rodríguez
Keyword(s):  
Gas Sensors ◽  
Cost Effective ◽  
Air Quality Monitoring ◽  
Outdoor Air ◽  
Promising Candidate ◽  
Post Process ◽  
Highly Sensitive ◽  
Monitoring Devices ◽  
Indoor And Outdoor ◽  
Selective Sensor

We report the growth of micrometer-sized In2O3 octahedral structures, which are next aligned in chains using dielectrophoresis on top of microhotplates with prepatterned electrodes and integrated heater to work as chemoresistive gas sensors. The devices are relatively fast (180 s), highly sensitive (response up to ~256%), and selective toward NO2 in humid environments, showing little response to O2 and ethanol, and being completely insensitive to CO and CH4. The here-presented fabrication method can be easily extended as a cost-effective post-process in CMOS-compatible microhotplate fabrication and, thus, represents a promising candidate for indoor and outdoor air quality monitoring devices.

scholarly journals Airborne Nanoparticle Detection By Sampling On Filters And Laser-Induced Breakdown Spectroscopy Analysis

2011 ◽  
Vol 304 ◽  
pp. 012012 ◽  
Author(s):  
Pascale Dewalle ◽  
Jean-Baptiste Sirven ◽  
Audrey Roynette ◽  
François Gensdarmes ◽  
Luana Golanski ◽  
...  
Keyword(s):  
Laser Induced Breakdown Spectroscopy ◽  
Spectroscopy Analysis ◽  
Breakdown Spectroscopy ◽  
Nanoparticle Detection ◽  
Laser Induced Breakdown ◽  
Airborne Nanoparticle

scholarly journals A novel graphene pressure sensor with zig–zag shaped piezoresistors for maximum strain coverage for enhancing the sensitivity of the pressure sensor

2021 ◽  
Vol 12 ◽  
pp. 14
Author(s):  
Meetu Nag ◽  
Ajay Kumar ◽  
Bhanu Pratap
Keyword(s):  
Pressure Sensor ◽  
Wearable Sensors ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
The Body ◽  
Optimized Design ◽  
Element Analysis ◽  
Highly Sensitive ◽  
And Performance ◽  
Piezoresistive Pressure Sensors

The demand for flexible and wearable sensors is increasing day by day due to varied applications in the biomedical field. Especially highly sensitive sensors are required for the detection of the low signal from the body. It is important to develop a pressure sensor that can convert the maximum input signal into the electrical output. In this paper, the design and performance of graphene piezoresistive pressure sensors have been investigated by zig–zag piezoresistors on the square diaphragm. On the applied pressure, deformation is sensed by the piezoresistors above the diaphragm. Finite element analysis is carried out to investigate the effect of zig–zag piezoresistors on the square diaphragm. Simulated results for the optimized design are obtained for an operating range of 0–100 psi for pressure sensitivity.

scholarly journals Real-time single airborne nanoparticle detection with nanomechanical resonant filter-fiber

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Silvan Schmid ◽  
Maksymilian Kurek ◽  
Jens Q. Adolphsen ◽  
Anja Boisen
Keyword(s):  
Real Time ◽  
Nanoparticle Detection ◽  
Airborne Nanoparticle

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Quantitative Measurements on the Ion Etching of TMV

1973 ◽  
Vol 31 ◽  
pp. 336-337
Author(s):  
Irwin Bendet ◽  
Nabil Rizk
Keyword(s):  
Electron Microscope ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Ion Current ◽  
Beam Diameter ◽  
Ion Etching ◽  
Preliminary Results ◽  
Quantitative Measurements ◽  
Monitoring Devices

Preliminary results reported last year on the ion etching of tobacco mosaic virus indicated that the diameter of the virus decreased more rapidly at 10KV than at 5KV, perhaps reaching a constant value before disappearing completely.In order to follow the effects of ion etching on TMV more quantitatively we have designed and built a second apparatus (Fig. 1), which incorporates monitoring devices for measuring ion current and vacuum as well as accelerating voltage. In addition, the beam diameter has been increased to approximately 1 cm., so that ten electron microscope grids can be exposed to the beam simultaneously.

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