scholarly journals Microfluidic and Micromachined/MEMS Devices for Separation, Discrimination and Detection of Airborne Particles for Pollution Monitoring

Micromachines ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 483 ◽  
Author(s):  
Daniel Puiu Poenar
Keyword(s):  
Optical Scattering ◽  
Pollution Monitoring ◽  
Detection Methods ◽  
Mems Devices ◽  
Micro Electro Mechanical Systems ◽  
Lab On Chip ◽  
Inorganic Particles ◽  
Advantages And Disadvantages ◽  
Air Quality Assessment ◽  
On Chip

Most of the microfluidics-related literature describes devices handling liquids, with only a small part dealing with gas-based applications, and a much smaller number of papers are devoted to the separation and/or detection of airborne inorganic particles. This review is dedicated to this rather less known field which has become increasingly important in the last years due to the growing attention devoted to pollution monitoring and air quality assessment. After a brief introduction summarizing the main particulate matter (PM) classes and the need for their study, the paper reviews miniaturized devices and/or systems for separation, detection and quantitative assessment of PM concentration in air with portable and easy-to-use platforms. The PM separation methods are described first, followed by the key detection methods, namely optical (scattering) and electrical. The most important miniaturized reported realizations are analyzed, with special attention given to microfluidic and micromachined or micro-electro-mechanical systems (MEMS) chip-based implementations due to their inherent capability of being integrated in lab-on-chip (LOC) type of smart microsystems with increased functionalities that can be portable and are easy to use. The operating principles and (when available) key performance parameters of such devices are presented and compared, also highlighting their advantages and disadvantages. Finally, the most relevant conclusions are discussed in the last section.

scholarly journals A review on lab-on-chip as a potential diagnostic tool for early detection of Plasmodium knowlesi

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Solihah Maketar ◽  
Nurhidanatasha Abu Bakar
Keyword(s):  
Early Detection ◽  
Diagnostic Tool ◽  
Malaria Infection ◽  
High Speed ◽  
Plasmodium Knowlesi ◽  
Acute Infection ◽  
Diagnostic Methods ◽  
Lab On Chip ◽  
Advantages And Disadvantages ◽  
On Chip

Massive elimination efforts have been done to control the malaria disease caused by the emergence of the fifth human malaria parasite known as Plasmodium knowlesi. Early detection of the parasite is important in treating malaria infection. Microscopic examination of Giemsa-stained thick and thin blood films is the gold standard for laboratory malaria diagnosis, while rapid diagnostic tests (RDTs), polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) are significant diagnostic techniques to detect acute infection. However, these methods have several limitations in which it could delay the treatment. The potential of lab-on-chip (LOC) as a point-of-care diagnostic tool for malaria fulfils the requirement of limitations where it is able to produce early detection of malaria infection. This review discusses advantages and disadvantages of malaria diagnostic methods as well as new approaches that could be used for high speed, sensitive and reliable malaria detection to prevent the disease from causing severe complications and even fatal if left untreated.

scholarly journals Polydimethylsiloxane mechanical properties: A systematic review

2021 ◽  
Vol 8 (6) ◽  
pp. 952-973
Author(s):  
Inês Teixeira ◽  
◽  
Inês Castro ◽  
Violeta Carvalho ◽  
Cristina Rodrigues ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Properties ◽  
American Chemical Society ◽  
Relevant Information ◽  
Chemical Society ◽  
Thermal Coefficient ◽  
Lab On Chip ◽  
Advantages And Disadvantages ◽  
On Chip

<abstract> <p>Polydimethylsiloxane (PDMS) has been a promising material for microfluidic, particularly in lab-on-chip. Due to the panoply of good physical, mechanical and chemical properties, namely, viscosity, modulus of elasticity, colour, thermal conductivity, thermal coefficient of expansion, its application has been increasingly requested in quite different areas. Despite such characteristics, there are also some drawbacks associated, and to overcome them, several strategies have been developed to modify PDMS. Given the great variety of relevant conducted research in this field, the present work aims to gather the most relevant information, the advantages and disadvantages of some of the techniques used, and also identify potential gaps and challenges in it. To this end, a systematic literature review was conducted by collecting data from four different databases, Science Direct, American Chemical Society, Scopus, and Springer. Two authors independently screened the references, extracted the key information, and assessed the quality of the included studies. After the analysis of the collected data, 25 studies were selected that addressed the various mechanical properties of PDMS and how to modify them in order to suit a particular application.</p> </abstract>

scholarly journals A Novel Fabrication Method for a Capacitive MEMS Accelerometer Based on Glass–Silicon Composite Wafers

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 102
Author(s):  
Yurong He ◽  
Chaowei Si ◽  
Guowei Han ◽  
Yongmei Zhao ◽  
Jin Ning ◽  
...  
Keyword(s):  
Mems Devices ◽  
Zero Bias ◽  
Micro Electro Mechanical Systems ◽  
Chip Area ◽  
Mems Accelerometer ◽  
Bias Stability ◽  
Etched Silicon ◽  
Vertical Interconnection ◽  
Capacitive Mems ◽  
On Chip

In this paper, we report a novel teeter-totter type accelerometer based on glass-silicon composite wafers. Unlike the ordinary micro-electro-mechanical systems (MEMS) accelerometers, the entire structure of the accelerometer, includes the mass, the springs, and the composite wafer. The composite wafer is expected to serve as the electrical feedthrough and the fixed capacitance plate at the same time, to simplify the fabrication process, and to save on chip area. It is manufactured by filling melted borosilicate glass into an etched silicon wafer and polishing the wafer flat. A sensitivity of 51.622 mV/g in the range of ±5 g (g = 9.8 m/s2), a zero-bias stability under 0.2 mg, and the noise floor with 11.28 µg/√Hz were obtained, which meet the needs of most acceleration detecting applications. The micromachining solution is beneficial for vertical interconnection and miniaturization of MEMS devices.

scholarly journals A Lab‐On‐chip Tool for Rapid, Quantitative, and Stage‐selective Diagnosis of Malaria

2021 ◽  
pp. 2004101
Author(s):  
Marco Giacometti ◽  
Francesca Milesi ◽  
Pietro Lorenzo Coppadoro ◽  
Alberto Rizzo ◽  
Federico Fagiani ◽  
...  
Keyword(s):  
Lab On Chip ◽  
On Chip

scholarly journals Integrated Magnetohydrodynamic Pump with Magnetic Composite Substrate and Laser-Induced Graphene Electrodes

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1113
Author(s):  
Mohammed Asadullah Khan ◽  
Jürgen Kosel
Keyword(s):  
Magnetic Flux ◽  
Flow Rate ◽  
Magnetic Composite ◽  
Propulsive Force ◽  
Closed Channel ◽  
Lab On Chip ◽  
Composite Substrate ◽  
On Chip ◽  
High Level ◽  
Moving Parts

An integrated polymer-based magnetohydrodynamic (MHD) pump that can actuate saline fluids in closed-channel devices is presented. MHD pumps are attractive for lab-on-chip applications, due to their ability to provide high propulsive force without any moving parts. Unlike other MHD devices, a high level of integration is demonstrated by incorporating both laser-induced graphene (LIG) electrodes as well as a NdFeB magnetic-flux source in the NdFeB-polydimethylsiloxane permanent magnetic composite substrate. The effects of transferring the LIG film from polyimide to the magnetic composite substrate were studied. Operation of the integrated magneto hydrodynamic pump without disruptive bubbles was achieved. In the studied case, the pump produces a flow rate of 28.1 µL/min. while consuming ~1 mW power.

scholarly journals Towards lab-on-chip ultrasensitive ethanol detection using photonic crystal waveguide operating in the mid infrared

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Rostamian ◽  
Ehsan Madadi-Kandjani ◽  
Hamed Dalir ◽  
Volker J. Sorger ◽  
Ray T. Chen
Keyword(s):  
Photonic Crystal ◽  
Slow Light ◽  
High Sensitivity ◽  
Guided Wave ◽  
Silicon On Insulator ◽  
Group Index ◽  
Photonic Crystal Waveguide ◽  
Mid Infrared ◽  
Lab On Chip ◽  
On Chip

Abstract Thanks to the unique molecular fingerprints in the mid-infrared spectral region, absorption spectroscopy in this regime has attracted widespread attention in recent years. Contrary to commercially available infrared spectrometers, which are limited by being bulky and cost-intensive, laboratory-on-chip infrared spectrometers can offer sensor advancements including raw sensing performance in addition to use such as enhanced portability. Several platforms have been proposed in the past for on-chip ethanol detection. However, selective sensing with high sensitivity at room temperature has remained a challenge. Here, we experimentally demonstrate an on-chip ethyl alcohol sensor based on a holey photonic crystal waveguide on silicon on insulator-based photonics sensing platform offering an enhanced photoabsorption thus improving sensitivity. This is achieved by designing and engineering an optical slow-light mode with a high group-index of n g  = 73 and a strong localization of modal power in analyte, enabled by the photonic crystal waveguide structure. This approach includes a codesign paradigm that uniquely features an increased effective path length traversed by the guided wave through the to-be-sensed gas analyte. This PIC-based lab-on-chip sensor is exemplary, spectrally designed to operate at the center wavelength of 3.4 μm to match the peak absorbance for ethanol. However, the slow-light enhancement concept is universal offering to cover a wide design-window and spectral ranges towards sensing a plurality of gas species. Using the holey photonic crystal waveguide, we demonstrate the capability of achieving parts per billion levels of gas detection precision. High sensitivity combined with tailorable spectral range along with a compact form-factor enables a new class of portable photonic sensor platforms when combined with integrated with quantum cascade laser and detectors.

scholarly journals A Stochastic Model to Describe the Scattering in the Response of Polysilicon MEMS

2021 ◽  
Vol 2 (1) ◽  
pp. 95
Author(s):  
Luca Dassi ◽  
Marco Merola ◽  
Eleonora Riva ◽  
Angelo Santalucia ◽  
Andrea Venturelli ◽  
...  
Keyword(s):  
Silicon Film ◽  
Micro Fabrication ◽  
Micro Electro Mechanical Systems ◽  
Local Fluctuations ◽  
Stochastic Framework ◽  
On Line ◽  
Chip Testing ◽  
On Chip ◽  
Time Required ◽  
Polycrystalline Silicon Film

The current miniaturization trend in the market of inertial microsystems is leading to movable device parts with sizes comparable to the characteristic length-scale of the polycrystalline silicon film morphology. The relevant output of micro electro-mechanical systems (MEMS) is thus more and more affected by a scattering, induced by features resulting from the micro-fabrication process. We recently proposed an on-chip testing device, specifically designed to enhance the aforementioned scattering in compliance with fabrication constraints. We proved that the experimentally measured scattering cannot be described by allowing only for the morphology-affected mechanical properties of the silicon films, and etch defects must be properly accounted for too. In this work, we discuss a fully stochastic framework allowing for the local fluctuations of the stiffness and of the etch-affected geometry of the silicon film. The provided semi-analytical solution is shown to catch efficiently the measured scattering in the C-V plots collected through the test structure. This approach opens up the possibility to learn on-line specific features of the devices, and to reduce the time required for their calibration.

scholarly journals A Tunable-Gain Transimpedance Amplifier for CMOS-MEMS Resonators Characterization

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 82
Author(s):  
Rafel Perelló-Roig ◽  
Jaume Verd ◽  
Sebastià Bota ◽  
Jaume Segura
Keyword(s):  
Cmos Technology ◽  
Open Loop ◽  
Transimpedance Amplifier ◽  
Mems Devices ◽  
Monolithically Integrated ◽  
Mems Resonators ◽  
Electromechanical Performance ◽  
Cmos Mems ◽  
Promising Solution ◽  
On Chip

CMOS-MEMS resonators have become a promising solution thanks to their miniaturization and on-chip integration capabilities. However, using a CMOS technology to fabricate microelectromechanical system (MEMS) devices limits the electromechanical performance otherwise achieved by specific technologies, requiring a challenging readout circuitry. This paper presents a transimpedance amplifier (TIA) fabricated using a commercial 0.35-µm CMOS technology specifically oriented to drive and sense monolithically integrated CMOS-MEMS resonators up to 50 MHz with a tunable transimpedance gain ranging from 112 dB to 121 dB. The output voltage noise is as low as 225 nV/Hz1/2—input-referred current noise of 192 fA/Hz1/2—at 10 MHz, and the power consumption is kept below 1-mW. In addition, the TIA amplifier exhibits an open-loop gain independent of the parasitic input capacitance—mostly associated with the MEMS layout—representing an advantage in MEMS testing compared to other alternatives such as Pierce oscillator schemes. The work presented includes the characterization of three types of MEMS resonators that have been fabricated and experimentally characterized both in open-loop and self-sustained configurations using the integrated TIA amplifier. The experimental characterization includes an accurate extraction of the electromechanical parameters for the three fabricated structures that enables an accurate MEMS-CMOS circuitry co-design.

Monitoring microbial growth on a microfluidic lab-on-chip with electrochemical impedance spectroscopic technique

2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Subhan Shaik ◽  
Aarthi Saminathan ◽  
Deepak Sharma ◽  
Jagdish A Krishnaswamy ◽  
D Roy Mahapatra
Keyword(s):  
Microbial Growth ◽  
Electrochemical Impedance ◽  
Spectroscopic Technique ◽  
Lab On Chip ◽  
On Chip ◽  
Electrochemical Impedance Spectroscopic
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