Name: terahertz microfluidic sensing using a parallel-plate waveguide sensor
Uploaded: 2012-08-30T13:00:00
Description: Watch this Scientific Journal Video about Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor at JoVE.com

Dette prosjektet ble støttet i en del av National Science Foundation og ved Air Force Research Laboratory gjennom kontakt programmet.

1. Sensor design og fabrikasjon <ol><li> Utforme en parallell-plate bølgeleder med en eller flere integrerte hulrom (eller &quot;riller&quot;). Se figurene 1 og 2. Geometri kan være basert på det som er gitt i våre tidligere publikasjoner 8,9 eller spesielt utformet for den aktuelle applikasjonen. Følgende generelle veiledende prinsippene er foreslått: <ol><li> Plateavstand: I dette forsøk en plateavstand på 1mm brukes for effektiv kobling til TE1 modus uten behov f...

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	<li>Kuswandi, B., Nuriman, ., Huskens, J., Verboom, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+sensing+systems+for+microfluidic+devices:+A+review.">Optical sensing systems for microfluidic devices: A review.</a> Ana. Chim. Acta. 601, 141-155 (2007).</li><li>Zhu, H., White, I. M., Suter, J. D., Zourob, M., Fan, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrated+refractive+index+optical+ring+resonator+detector+for+capillary+electrophoresis.">Integrated refractive index optical ring resonator detector for capillary electrophoresis.</a> Anal. Chem. 79, 930-937 (2007).</li><li>Kurt, H., Citrin, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coupled-resonator+optical+waveguides+for+biochemical+sensing+of+nanoliter+volumes+of+analyte+in+the+terahertz+region.">Coupled-resonator optical waveguides for biochemical sensing of nanoliter volumes of analyte in the terahertz region.</a> Appl. Phys. Lett. 87, 241119 (2005).</li><li>Debus, C., Bolivar, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequency+selective+surfaces+for+high+sensitivity+terahertz+sensing.">Frequency selective surfaces for high sensitivity terahertz sensing.</a> Appl. Phys. Lett. 91, 184102 (2007).</li><li>Harsha, S. S., Laman, N., Grischkowsky, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Q+terahertz+Bragg+rsonances+within+a+metal+parallel+plate+waveguide.">High-Q terahertz Bragg rsonances within a metal parallel plate waveguide.</a> Appl. Phys. Lett. 94, 091118 (2009).</li><li>Mendis, R., Mittleman, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+lowest-order+transverse-electric+(TE1)+and+transverse-magnetic+(TEM)+modes+of+the+parallel-plate+waveguide+for+terahertz+pulse+applications.">Comparison of the lowest-order transverse-electric (TE1) and transverse-magnetic (TEM) modes of the parallel-plate waveguide for terahertz pulse applications.</a> Optics Express. 17, 14839-14850 (2009).</li><li>Mendis, R., Mittleman, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+investigation+of+the+lowest-order+transverse-electric+(TE1)+mode+of+the+parallel-plate+waveguide+for+THz+pulse+propagation.">An investigation of the lowest-order transverse-electric (TE1) mode of the parallel-plate waveguide for THz pulse propagation.</a> JOSA B. 26, A6-A13 (2009).</li><li>Astley, V., McCracken, B., Mendis, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+rectangular+resonant+cavities+in+terahertz+parallel-plate+waveguides.">Analysis of rectangular resonant cavities in terahertz parallel-plate waveguides.</a> Opt. Lett. 36, 1452 (2011).</li><li>Mendis, R., Astley, V., Liu, J., Mittleman, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Terahertz+microfluidic+sensor+based+on+a+parallel-plate-waveguide+resonant+cavity.">Terahertz microfluidic sensor based on a parallel-plate-waveguide resonant cavity.</a> Appl. Phys. Lett. 95, 171113 (2009).</li><li>Astley, V., Reichel, K., Jones, J., Mendis, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Terahertz+multichannel+microfluidic+sensor+based+on+parallel-plate+waveguide+resonant+cavities.">Terahertz multichannel microfluidic sensor based on parallel-plate waveguide resonant cavities.</a> Appl. Phys. Lett. , (2012).</li></ol>

Det bør bemerkes at brytningsindeksen for væsken under test bestemmes bare ved frekvensen av hulrommet resonans, ikke over en bred båndbredde. Dette har noen klare fordeler. Først, selv om våre målinger har gjort bruk av en bredbåndstilkobling terahertz kilde for karakterisering formål, kunne man også bygge en tilsvarende sensing system med en enkelt-frekvens THz kilde med bare en begrenset grad av frekvens tunability, en tilnærming som kan være mye billigere og mer kompakt. Sekund, kan det sensing tilnærmin...

<table border="1"><tbody><tr><td> Navnet på reagensen </td><td> Selskapet </td><td> Katalognummer </td><td> Kommentarer (valgfritt) </td></tr><tr><td> 10 pl sprøyte </td><td> Hamilton </td><td> 80314 </td><td> Høy presisjon sprøyte </td></tr><tr><td> Flytende alkaner </td><td> Acros Organics </td><td></td><td> Prøver for kalibrering og testing </td></tr><tr><td></td><td></td><td></td><td> Ingen spesifikk utstyr kreves. Egnede testmaterialene og løsemidler overlates til eksperimentator skjønn. De med høy presisjon sprøyter som brukes i denne prosedyren er oppført i tabellen nedenfor, men eksperimentator kan ønske å bruke sprøyter med en annen volum eller design, inkludert digitale sprøyter for forbedret nøyaktighet. Testen alkaner anvendt i dette forsøk er også oppført. </td></tr></tbody></table>

terahertz microfluidic sensing using a parallel-plate waveguide sensor

Brytningsindeks (RI) sensing er en kraftig noninvasive og label-fri sensing teknikk for identifisering, deteksjon og overvåking av microfluidic prøver med et bredt spekter av mulige sensor design som interferometre og resonatorer 1,2. Fleste av de eksisterende RI sensing applikasjoner fokusere på biologiske materialer i vandige oppløsninger i synlige og IR frekvenser, for eksempel DNA-hybridisering og genomsekvensering. På terahertz frekvenser, bruksområder er kvalitetskontroll, overvåking av industrielle prosesser og sensing og deteksjon søknader som involverer upolare stoffer. Flere potensielle design for brytningsindeks sensorer i terahertz regime eksisterer, inkludert fotoniske krystaller waveguides 3, asymmetriske split-ring resonatorer 4 og fotoniske band gap strukturer integrert i parallell-plate bølgeledere 5. Mange av disse motiver er basert på optiske resonatorer slik som ringereller hulrom. Resonans frekvenser av disse strukturene er avhengig brytningsindeksen av materialet i eller rundt resonatoren. Ved å overvåke endringer i resonansefrekvensen brytningsindeksen av en prøve kan måles nøyaktig, og dette i sin tur kan brukes til å identifisere et materiale, overvåke kontaminering eller fortynning, osv. Sensoren motivet vi bruker her er basert på en enkel parallell-plate bølgelederen 6,7. Et rektangulært spor maskinert inn en face fungerer som en resonanskavitet (figurene 1 og 2). Når terahertz stråling er koplet inn i bølgelederen og forplanter i laveste-ordens tverrgående-elektrisk (TE 1)-modus, er resultatet en enkelt sterk resonans funksjonen med en avstembar resonansfrekvens som er avhengig av geometrien av sporet 6,8. Denne rillen kan fylles med upolare flytende microfluidic prøvene som forårsaker et skifte i den observerte resonansfrekvens som avhenger av mengden av liquid i sporet og dens brytningsindeks ni. Vår teknikk har en fordel fremfor andre terahertz teknikker i sin enkelhet, både i fabrikasjon og gjennomføring, siden prosedyren kan utføres med standard laboratorieutstyr uten behov for et rent rom eller noen spesiell fabrikasjon eller eksperimentelle teknikker. Det kan også lett utvides til flerkanals drift ved inkorporering av flere spor 10. I denne videoen vil vi beskrive vår komplette eksperimentell prosedyre, fra utformingen av sensoren til dataanalyse og bestemmelse av prøven brytningsindeks.

Watch this Scientific Journal Video about Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor at JoVE.com

Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor

Fremgangsmåten for implementering av en brytningsindeks sensor for terahertz frekvenser basert på en rillet parallell-plate waveguide geometri er beskrevet her. Metoden gir en måling av brytningsindeksen for et lite volum av væske gjennom overvåking av skift i resonansfrekvensen for bølgelederstruktur

Terahertz Microfluidic Sensing bruker en parallell-plate Waveguide Sensor

Refractive index (RI) sensing is a powerful noninvasive and label-free sensing technique for the identification, detection and monitoring of microfluidic ...

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Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on photoconduction, which has been one of the most commonly used techniques for terahertz generation 1-8. Terahertz generation in a photoconductive emitter is achieved by pumping an ultrafast photoconductor with a pulsed or heterodyned laser illumination. The induced photocurrent, which follows the envelope of the pump laser, is routed to a terahertz radiating antenna connected to the photoconductor contact electrodes to generate terahertz radiation. Although the quantum efficiency of a photoconductive emitter can theoretically reach 100%, the relatively long transport path lengths of photo-generated carriers to the contact electrodes of conventional photoconductors have severely limited their quantum efficiency. Additionally, the carrier screening effect and thermal breakdown strictly limit the maximum output power of conventional photoconductive terahertz sources. To address the quantum efficiency limitations of conventional photoconductive terahertz emitters, we have developed a new photoconductive emitter concept which incorporates a plasmonic contact electrode configuration to offer high quantum-efficiency and ultrafast operation simultaneously. By using nano-scale plasmonic contact electrodes, we significantly reduce the average photo-generated carrier transport path to photoconductor contact electrodes compared to conventional photoconductors 9. Our method also allows increasing photoconductor active area without a considerable increase in the capacitive loading to the antenna, boosting the maximum terahertz radiation power by preventing the carrier screening effect and thermal breakdown at high optical pump powers. By incorporating plasmonic contact electrodes, we demonstrate enhancing the optical-to-terahertz power conversion efficiency of a conventional photoconductive terahertz emitter by a factor of 50 10.

We describe methods for the design, fabrication, and experimental characterization of plasmonic photoconductive emitters, which offer two orders of magnitude higher terahertz power levels compared to conventional photoconductive emitters.

Design, Fabrikasjon, og eksperimentell karakterisering av Plasmonic Photoconductive Terahertz Sendere

In this video article we present a detailed demonstration of a highly efficient method for generating terahertz waves. Our technique is based on ...

How to Build a Vacuum Spring-transport Package for Spinning Rotor Gauges

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to 1.0 Pa. In this application, the SRGs are frequently transported to laboratories for calibration. Events can occur during transportation that change the rotor surface conditions, thus changing the calibration factor. To assure calibration stability, a spring-transport mechanism is often used to immobilize the rotor and keep it under vacuum during transport. It is also important to transport the spring-transport mechanism using packaging designed to minimize the risk of damage during shipping. In this manuscript, a detailed description is given on how to build a robust spring-transport mechanism and shipping container. Together these form a spring-transport package. The spring-transport package design was tested using drop-tests and the performance was found to be excellent. The present spring-transport mechanism design keeps the rotor immobilized when experiencing shocks of several hundred g (g = 9.8 m/sec2 and is the acceleration due to gravity), while the shipping container assures that the mechanism will not experience shocks greater than about 100 g during common shipping mishaps (as defined by industry standards).

Here we describe how to build a robust spring-transport mechanism for a spinning rotor gauge. This device securely immobilizes the rotor and keeps it under vacuum during transportation. We also describe packaging that minimizes the risk of damage during transport. Tests show our design works for typical shocks during transport.

Hvordan bygge en Vacuum Spring-transport Package for Spinning Rotor Gauges

The spinning rotor gauge (SRG) is a high-vacuum gauge often used as a secondary or transfer standard for vacuum pressures in the range of 1.0 x 10-4 Pa to ...

Fabrication of Nanopillar-Based Split Ring Resonators for Displacement Current Mediated Resonances in Terahertz Metamaterials

Terahertz (THz) split ring resonator (SRR) metamaterials (MMs) has been studied for gas, chemical, and biomolecular sensing applications because the SRR is not affected by environmental characteristics such as the temperature and pressure surrounding the resonator. Electromagnetic radiation in THz frequencies is biocompatible, which is a critical condition especially for the application of the biomolecular sensing. However, the quality factor (Q-factor) and frequency responses of traditional thin-film based split ring resonator (SRR) MMs are very low, which limits their sensitivities and selectivity as sensors. In this work, novel nanopillar-based SRR MMs, utilizing displacement current, are designed to enhance the Q-factor up to 450, which is around 45 times higher than that of traditional thin-film-based MMs. In addition to the enhanced Q-factor, the nanopillar-based MMs induce a larger frequency shifts (17 times compared to the shift obtained by the traditional thin-film based MMs). Because of the significantly enhanced Q-factors and frequency shifts as well as the property of biocompatible radiation, the THz nanopillar-based SRR are ideal MMs for the development of biomolecular sensors with high sensitivity and selectivity without inducing damage or distortion to biomaterials. A novel fabrication process has been demonstrated to build the nanopillar-based SRRs for displacement current mediated THz MMs. A two-step gold (Au) electroplating process and an atomic layer deposition (ALD) process are used to create sub-10 nm scale gaps between Au nanopillars. Since the ALD process is a conformal coating process, a uniform aluminum oxide (Al2O3) layer with nanometer-scale thickness can be achieved. By sequentially electroplating another Au thin film to fill the spaces between Al2O3 and Au, a close-packed Au-Al2O3-Au structure with nano-scale Al2O3 gaps can be fabricated. The size of the nano-gaps can be well defined by precisely controlling the deposition cycles of the ALD process, which has an accuracy of 0.1 nm.

A protocol for the design and fabrication of a novel nanopillar-based split ring resonator (SRR) is presented.

Fabrikasjon av Nanopillar-baserte Split Ring resonatorer for Displacement Nåværende mediert Resonans i terahertz Metamaterials

Terahertz (THz) split ring resonator (SRR) metamaterials (MMs) has been studied for gas, chemical, and biomolecular sensing applications because the SRR ...

Femtosecond Laser Filaments for Use in Sub-Diffraction-Limited Imaging and Remote Sensing

Probing remote matter with laser light is a ubiquitous technique used in circumstances as diverse as laser-induced breakdown spectroscopy and barcode scanners. In classical optics, the intensity that can be brought to bear on a remote target is limited by the spot size of the laser at the distance of the target. This spot size has a lower bound determined by the diffraction limit of classical optics. However, amplified femtosecond laser pulses generate intensity sufficient to modify the refractive index of the ambient air and undergo self-focusing. This self-focusing effect leads to the generation of highly intense laser filaments which maintain their intensity and small sub-millimeter diameter size at distances well beyond the classical Rayleigh length. Such intensity provides the capability of remote scanning, imaging, sensing, and spectroscopy with enhanced spatial resolution. We describe a technique for generating filaments with a femtosecond regenerative chirped-pulse amplifier, and for using the resulting filament to conduct imaging and spectroscopic measurements at remote distances of at least several meters.

High-intensity femtosecond pulses of laser light can undergo cycles of Kerr self-focusing and plasma defocusing, propagating an intense sub-millimeter-diameter beam over long distances. We describe a technique for generating and using these filaments to perform remote imaging and sensing beyond the classical diffraction limits of linear optics.

Femtosecond Laser filamenter for bruk i Sub-Diffraction-begrenset Imaging og fjernmåling

Probing remote matter with laser light is a ubiquitous technique used in circumstances as diverse as laser-induced breakdown spectroscopy and barcode ...

A Silicon-tipped Fiber-optic Sensing Platform with High Resolution and Fast Response

In this article, we introduce an innovative and practically promising fiber-optic sensing platform (FOSP) that we proposed and demonstrated recently. This FOSP relies on a silicon Fabry-Perot interferometer (FPI) attached to the fiber end, referred to as Si-FOSP in this work. The Si-FOSP generates an interferogram determined by the optical path length (OPL) of the silicon cavity. Measurand alters the OPL and thus shifts the interferogram. Due to the unique optical and thermal properties of the silicon material, this Si-FOSP exhibits an advantageous performance in terms of sensitivity and speed. Furthermore, the mature silicon fabrication industry endows the Si-FOSP with excellent reproducibility and low cost toward practical applications. Depending on the specific applications, either a low-finesse or high-finesse version will be utilized, and two different data demodulation methods will be adopted accordingly. Detailed protocols for fabricating both versions of the Si-FOSP will be provided. Three representative applications and their according results will be shown. The first one is a prototype underwater thermometer for profiling the ocean thermoclines, the second one is a flow meter to measure flow speed in the ocean, and the last one is a bolometer used for monitoring exhaust radiation from magnetically confined high-temperature plasma.

This work reports an innovative silicon-tipped fiber-optic sensing platform (Si-FOSP) for high-resolution and fast-response measurement of a variety of physical parameters, such as temperature, flow, and radiation. Applications of this Si-FOSP span from oceanographic research, mechanical industry, to fusion energy research.

En silisium-tipped fiberoptisk Sensing plattform med høy oppløsning og rask respons

In this article, we introduce an innovative and practically promising fiber-optic sensing platform (FOSP) that we proposed and demonstrated recently. This ...

Terahertz Imaging and Characterization Protocol for Freshly Excised Breast Cancer Tumors

This manuscript presents a protocol to handle, characterize, and image freshly excised human breast tumors using pulsed terahertz imaging and spectroscopy techniques. The protocol involves terahertz transmission mode at normal incidence and terahertz reflection mode at an oblique angle of 30&#176;. The collected experimental data represent time domain pulses of the electric field. The terahertz electric field signal transmitted through a fixed point on the excised tissue is processed, through an analytical model, to extract the refractive index and absorption coefficient of the tissue. Utilizing a stepper motor scanner, the terahertz emitted pulse is reflected from each pixel on the tumor providing a planar image of different tissue regions. The image can be presented in time or frequency domain. Furthermore, the extracted data of the refractive index and absorption coefficient at each pixel are utilized to provide a tomographic terahertz image of the tumor. The protocol demonstrates clear differentiation between cancerous and healthy tissues. On the other hand, not adhering to the protocol can result in noisy or inaccurate images due to the presence of air bubbles and fluid remains on the tumor surface. The protocol provides a method for surgical margins assessment of breast tumors.

Freshly excised human breast cancer tumors are characterized with terahertz spectroscopy and imaging following fresh tissue handling protocols. Tissue positioning is taken into consideration to enable effective characterization while providing analysis in a timely manner for future intraoperative applications.

Terahertz imaging og karakterisering protokoll for nyskåret brystkreft svulster

This manuscript presents a protocol to handle, characterize, and image freshly excised human breast tumors using pulsed terahertz imaging and spectroscopy ...

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future combustion engine vehicle technology may emit large amounts of sub-23 nm particles. The Horizon 2020 funded project DownToTen (DTT) developed a sampling and measurement method to characterize particle emissions in this currently unregulated size range. A PN measurement system was developed based on an extensive review of the literature and laboratory experiments testing a variety of PN measurement and sampling approaches. The measurement system developed is characterized by high particle penetration and versatility, which enables the assessment of primary particles, delayed primary particles, and secondary aerosols, starting from a few nanometers in diameter. This paper provides instruction on how to install and operate this Portable Emission Measurement System (PEMS) for Real Drive Emissions (RDE) measurements and assess particle number emissions below the current legislative limit of 23 nm.

Presented here is the DownToTen (DTT) portable emission measurement system to assess real driving automotive emissions of sub-23 nm particles.

Måling av Sub-23 Nanometer Reelle kjøring partikkelnummerutslipp ved hjelp av portable DownToTen Sampling System

The current particle size threshold of the European Particle Number (PN) emission standards is 23 nm. This threshold could change because future ...

Mechanoluminescent Visualization of Crack Propagation for Joint Evaluation

In this study, methods for the mechanoluminescent (ML) visualization of crack propagation and mechanical behavior to evaluate adhesive joints are demonstrated and explained. The first step involved sample preparation; an air spray was used to apply ML paint to the surface of the adhesive joint specimens. The performance of the ML sensor was described to examine the measurement conditions. The results of ML sensing during a double cantilever beam (DCB) test and a lap-shear (LS) test are demonstrated as these are the most frequently and widely used methods for evaluating adhesives. Originally, it was difficult to directly quantify the crack tip and strain/stress distribution and concentration because the crack tip was too small, and the effects of the strain could not be observed. The mechanoluminescence, crack propagation, and mechanical behavior during mechanical testing can be visualized via the ML pattern during the adhesive evaluation. This allows for the recognition of the precise position of the crack tips and other mechanical behaviors related to structural failure.

In this study, a protocol is presented that describes the use of mechanoluminescent (ML) visualization for monitoring crack propagation and mechanical behavior during adhesive joint evaluation testing.

Mekanoluminescerende visualisering av sprekkutbredelse for felles evaluering

In this study, methods for the mechanoluminescent (ML) visualization of crack propagation and mechanical behavior to evaluate adhesive joints are ...

Fabrication of a Fabry-P&amp;#233;rot Etalon for Application in Trace-Gas Spectroscopy

Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-P&#233;rot Etalon

Fabry-P&#233;rot etalons (FPE) have found their way into many applications. In fields such as spectroscopy, telecommunications, and astronomy, FPEs are used for their high sensitivity as well as their exceptional filtering capability. However, air-spaced etalons with high finesse are usually built by specialized facilities. Their production requires a clean room, special glass handling, and coating machinery, meaning commercially available FPEs are sold for a high price. In this article, a new and cost-effective method to fabricate fiber-coupled FPEs with standard photonic laboratory equipment is presented. The protocol should serve as a step-by-step guide for the construction and characterization of these FPEs. We hope this&#160;will enable researchers to conduct fast and cost-effective prototyping of FPEs for various fields of application. The FPE, as presented here, is used for spectroscopic applications. As shown in the representative results section via proof of principle measurements of water vapor in ambient air, this FPE has a finesse of 15, which is sufficient for the photothermal detection of trace concentrations of gases.

Author Spotlight: Fabrication of a Low-Cost, Fiber-Coupled, and Air-Spaced Fabry-P&amp;#233;rot Etalon  

This protocol describes the construction of a low-cost, discrete, fiber-coupled, and air-spaced Fabry-Perot etalon with various applications, such as in trace-gas spectroscopy. The fabrication is possible in any facility with standard optical laboratory equipment available.

Fabrikasjon av en billig, fiberkoblet og luftdistansert Fabry-Pérot Etalon

Fabry-P&#233;rot etalons (FPE) have found their way into many applications. In fields such as spectroscopy, telecommunications, and astronomy, FPEs are ...

Mikrofluidiske kanalbaserte myke elektroder for kapasitiv trykkføling

Microfluidic Channel-Based Soft Electrodes and Their Application in Capacitive Pressure Sensing

Flexible and stretchable electrodes are essential components in soft artificial sensory systems. Despite recent advances in flexible electronics, most electrodes are either restricted by the patterning resolution or the capability of inkjet printing with high-viscosity super-elastic materials. In this paper, we present a simple strategy to fabricate microchannel-based stretchable composite electrodes, which can be achieved by scraping elastic conductive polymer composites (ECPCs) into lithographically embossed microfluidic channels. The ECPCs were prepared by a volatile solvent evaporation method, which achieves a uniform dispersion of carbon nanotubes (CNTs) in a polydimethylsiloxane (PDMS) matrix. Compared to conventional fabrication methods, the proposed technique can facilitate the rapid fabrication of well-defined stretchable electrodes with high-viscosity slurry. Since the electrodes in this work were made up of all-elastomeric materials, strong interlinks can be formed between the ECPCs-based electrodes and the PDMS-based substrate at the interfaces of the microchannel walls, which allows the electrodes to exhibit mechanical robustness under high tensile strains. In addition, the mechanical-electric response of the electrodes was also systematically studied. Finally, a soft pressure sensor was developed by combining a dielectric silicone foam and an interdigitated electrodes (IDE) layer, and this demonstrated great potential for pressure sensors in soft robotic tactile sensing applications.

Forfatter Spotlight: Mikrofluidiske kanalbaserte myke elektroder og deres anvendelse i kapasitiv trykkføling  

Flexible electrodes have a wide range of applications in soft robotics and wearable electronics. The present protocol demonstrates a new strategy to fabricate highly stretchable electrodes with high resolution via lithographically defined microfluidic channels, which paves the way for future high-performance soft pressure sensors.

Mikrofluidiske kanalbaserte myke elektroder og deres anvendelse i kapasitiv trykkavkjenning

Flexible and stretchable electrodes are essential components in soft artificial sensory systems. Despite recent advances in flexible electronics, most ...