מחקר זה מומן על ידי NSERC, קנדה.

<ol>
	<li>Mairhofer, J., Roppert, K., Ertl, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+Systems+for+Pathogen+Sensing.">Microfluidic Systems for Pathogen Sensing.</a> A Review. Sensors. 9, 4804-4823 (2009).</li><li>Jokerst, J. J., Emory, J. M., Henry, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+microfluidics+for+environmental+analysis.">Advances in microfluidics for environmental analysis.</a> Analyst. 137, 24-34 (2012).</li><li>Neethirajan, N., Kobayashi, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidics+for+food,+agriculture+and+biosystems+industries.">Microfluidics for food, agriculture and biosystems industries.</a> Lab on a Chip. 11, 1574-1586 (2011).</li><li>Amarie, D., Alileche, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+Devices+Integrating+Microcavity+Surface-Plasmon-Resonance+Sensors:+Glucose+Oxidase+Binding-Activity+Detection.">Microfluidic Devices Integrating Microcavity Surface-Plasmon-Resonance Sensors: Glucose Oxidase Binding-Activity Detection.</a> Analytical Chemistry. 82, 343-352 (2010).</li><li>Vollmer, F., Arnold, S., Keng, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single+virus+detection+from+the+reactive+shift+of+a+whispering-gallery+mode.">Single virus detection from the reactive shift of a whispering-gallery mode.</a> PNAS. 105, 20701-20704 (2008).</li><li>Armani, A. M., Kulkarni, R. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-Molecule+Detection+with+Optical+Microcavities.">Single-Molecule Detection with Optical Microcavities.</a> Science. 317, 783-787 (2007).</li><li>Arnold, S., Shopova, I., Holler, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whispering+gallery+mode+bio-sensor+for+label-free+detection+of+single+molecules:+thermo-optic+vs.+reactive+mechanism.">Whispering gallery mode bio-sensor for label-free detection of single molecules: thermo-optic vs. reactive mechanism.</a> Optics Express. 18, 281-287 (2009).</li><li>Vollmer, F., Braun, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+detection+by+optical+shift+of+a+resonant+microcavity.">Protein detection by optical shift of a resonant microcavity.</a> Applied Physics Letters. 80, 4057-4059 (2002).</li><li>Rayleigh, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+problem+of+the+whispering+gallery.">The problem of the whispering gallery.</a> Philosophical Magazine. 20, 115-120 (1910).</li><li>White, I. M., Oveys, H., 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=Liquid-core+optical+ring-resonator+sensors.">Liquid-core optical ring-resonator sensors.</a> Optics Letters. 9, 1319-1321 (2006).</li><li>Rodriguez, J. R., Bianucci, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whispering+gallery+modes+in+hollow+cylindrical+microcavities+containing+silicon+nanocrystals.">Whispering gallery modes in hollow cylindrical microcavities containing silicon nanocrystals.</a> Applied Physics Letters. 92, 131119 (2008).</li><li>Bianucci, P., Rodriguez, J. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whispering+gallery+modes+in+silicon+nanocrystal+coated+microcavities.">Whispering gallery modes in silicon nanocrystal coated microcavities.</a> Physica Status Solidi A. 206, 965 (2009).</li><li>Hessel, C. M., Henderson, E. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrogen+Silsesquioxane:+A+Molecular+Precursor+for+Nanocrystalline+Si-SiO2+Composites+and+Freestanding+Hydride-Surface-Terminated+Silicon+Nanoparticles.">Hydrogen Silsesquioxane: A Molecular Precursor for Nanocrystalline Si-SiO2 Composites and Freestanding Hydride-Surface-Terminated Silicon Nanoparticles.</a> Chemistry of Materials. 18, 6139-6146 (2006).</li><li>Poon, A. W., Chang, R. K., Lock, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spiral+morphology-dependent+resonances+in+an+optical+fiber:+effects+of+fiber+tilt+and+focused+Gaussian+beam+illumination.">Spiral morphology-dependent resonances in an optical fiber: effects of fiber tilt and focused Gaussian beam illumination.</a> Opt. Lett. 23, 1105-1107 (1998).</li><li>Silverstone, J. W., McFarlane, S., Manchee, C. P. K., Meldrum, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultimate+resolution+for+sensing+with+microcavities.">Ultimate resolution for sensing with microcavities.</a> Optics Express. 20, 8284-8295 (2012).</li><li>Stancik, A. L., Brauns, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+asymmetric+lineshape+for+fitting+infrared+absorption+spectra.">A simple asymmetric lineshape for fitting infrared absorption spectra.</a> Vibrational Spectroscopy. 47, 66-69 (2008).</li><li>Lomb, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Least-squares+frequency+analysis+of+unequally+spaced+data.">Least-squares frequency analysis of unequally spaced data.</a> Astrophysics and Space Science. 39, 447-462 (1976).</li><li>Scott, R. P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+thermodynamic+properties+of+methanol-water+association+and+its+effect+on+solute+retention+in+liquid+chromatography.">The thermodynamic properties of methanol-water association and its effect on solute retention in liquid chromatography.</a> Analyst. 125, 1543-1547 (2000).</li><li>Manchee, C. P. K., Zamora, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refractometric+sensing+with+fluorescent-core+microcavities.">Refractometric sensing with fluorescent-core microcavities.</a> Optics Express. 19, 21540-21551 (2011).</li><li>Teraoka, I., Arnold, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancing+Sensitivity+of+a+Whispering+Gallery+Mode+Microsphere+Sensor+by+a+High-Refractive+Index+Surface.">Enhancing Sensitivity of a Whispering Gallery Mode Microsphere Sensor by a High-Refractive Index Surface.</a> Layer. J. Opt. Soc. Am. B. 23, 1434-1441 (2006).</li><li>Huang, G., Bolanos Quinones, V. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rolled-up+optical+microcavities+with+subwavelength+wall+thicknesses+for+enhanced+liquid+sensing+applications.">Rolled-up optical microcavities with subwavelength wall thicknesses for enhanced liquid sensing applications.</a> ACS Nano. 4, 3123-3130 (2010).</li><li>Fan, X. D., White, I. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Overview+of+novel+integrated+optical+ring+resonator+bio/chemical+sensors.">Overview of novel integrated optical ring resonator bio/chemical sensors.</a> Proceedings of the Society of Photo-Optical Instrumentation Engineers (SPIE). 6452, M4520-M4520 (2007).</li><li>White, I. M., Zhu, , et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refractometric+sensors+for+lab-on-a-chip+based+on+optical+ring+resonators.">Refractometric sensors for lab-on-a-chip based on optical ring resonators.</a> IEEE Sensors J. 7, 28-35 (2007).</li><li>Li, H., 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=Characterization+of+sensing+capability+of+optofluidic+ring+resonator+biosensors.">Characterization of sensing capability of optofluidic ring resonator biosensors.</a> Applied Physics Letters. 97, 011105 (2010).</li><li>Zamora, V., D&#237;ez, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Refractometric+sensor+based+on+whispering+gallery+modes+of+thin+capillaries.">Refractometric sensor based on whispering gallery modes of thin capillaries.</a> Optics Express. 15, 12011-12016 (2007).</li><li>Suter, J. D., White, I. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Label-free+quantitative+DNA+detection+using+the+liquid+core+optical+ring+resonator.">Label-free quantitative DNA detection using the liquid core optical ring resonator.</a> Biosensors and Bioelectronics. 23, 1003-1009 (2008).</li><li>White, I. M., Oveys, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrated+multiplexed+biosensors+based+on+liquid+core+optical+ring+resonators+and+antiresonant+reflecting+optical+waveguides.">Integrated multiplexed biosensors based on liquid core optical ring resonators and antiresonant reflecting optical waveguides.</a> Applied Physics Letters. 89, 191106 (2006).</li><li>Yang, G., White, I. 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=An+opto-fluidic+ring+resonator+biosensor+for+the+detection+of+organophosphorus+pesticides.">An opto-fluidic ring resonator biosensor for the detection of organophosphorus pesticides.</a> Sensors and Actuators B: Chemical. 133, 105-112 (2008).</li><li>Zhu, H., Dale, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+and+Label-Free+Detection+of+Breast+Cancer+Biomarker+CA15-3+in+Clinical+Human+Serum+Samples+with+Optofluidic+Ring+Resonator+Sensors.">Rapid and Label-Free Detection of Breast Cancer Biomarker CA15-3 in Clinical Human Serum Samples with Optofluidic Ring Resonator Sensors.</a> Anal. Chem. 81, 9858-9865 (2009).</li><li>Redding, B., Marchena, E., et al. <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+raised-microdisk+whispering-gallery-mode+characterization+techniques.">Comparison of raised-microdisk whispering-gallery-mode characterization techniques.</a> Optics Letters. 35, 998-1000 (2010).</li></ol>

אין לנו מה למסור.

microcavities פלורסנט ליבות יכול לשמש כחיישני refractometric. אמנם יש דוגמאות בודדות של microtubes &quot;מגולגל&quot; שיכול לשמש כחיישני microfluidic, 22 בהשוואה לmicrotubes, נימים תהיינה קלות יותר להשתלב setups microfluidic ויש יתרונות מעשיים רבים, שכן הם טפלו בקלות ופשוטה לממשק עם ניתוח התקנה. שימוש בשי...

מערכות חישה כימית הדורשות נפחי מדגם קטנים בלבד, וכי ניתן לשלב את התקני כף יד או שדה מפורמטים יכולות להוביל לפיתוח של מגוון רחב של טכנולוגיות חדשות. טכנולוגיות מסוג זה יכול לכלול אבחון שדה למחלות ומזיקים, 1, 2 מזהמים סביבתיים ובטיחות מזון. 3 מספר טכנולוגיות נבדקות באופן פעיל לחיישנים כימיים microfluidic, עם מכשירים הבוסס על הפיזיקה של תהודות plasmon שטח (SPR) מהמתקדמים ביותר. 4 חיישנים אלה נמצאים כעת מסוגלים לאתר ביומולקולות ספציפית רבה וזכו להצלחה מסחרית, אם כי בעיקר כציוד מעבדה בקנה מידה גדול. 5 בשנים האחרונות, microcavities האופטי עלה להתחרות עם מערכות SPR מבוססים. Microcavities יכול להיות רגיש להפליא, עם יכולת מוכחת לגילוי וירוסים בודדים 6 ואולי אפילו היחידה ביומולקולות <sעד&gt; 7 (אשר נותר שנוי במחלוקת כלשהי, 8 אך אין ספק שמגבלות זיהוי ההמוניות הן 9 קטנים). בmicrocavities, מנגנון זיהוי מסתמך על שינויים בתהודות האופטיות הנגרמות על ידי הנוכחות של אנליטי במסגרת פרופיל השדה החשמלי של התהודה. בדרך כלל, אנליטי נתון יגרום לשינוי בתהודה בתדר מרכזי, ראות, או linewidth. כמו במערכות SPR, microcavities יכול לשמש כחיישני refractometric אינם ספציפיים, או כbiosensors פונקציונלי לניתוח ספציפי. microstructures דיאלקטרי עם חתך עגול (למשל microspheres, דיסקים, או צילינדרים) מתאפיין בתהודות אלקטרומגנטיים המכונות מצבים לוחשים הגלריה, או WGMs, מונח שראשיתה בחקירות של הלורד Rayleigh של אפקטים אקוסטיים מקבילים. 10 בעיקרון, WGM אופטי מתרחש כאשר גל circumnavigates צלב של מעגליection ידי השתקפות מוחלטת פנימית, וחוזר לנקודת ההתחלה שלו בשלב זה. דוגמה לתהודה אלקטרומגנטית לmicrosphere סיליקה מודגמת באיור 1 א. תהודה זו מאופיינת במקסימום אחד בכיוון רדיאלי (n = 1), ואילו סך של 53 אורכי גל שיתאים סביב הקו המשווה (l = 53), רק שחלקם הראה. חלק החלוף של עוצמת השדה משתרע לתוך המדיום מחוץ לגבולות התחום, ולכן WGM microsphere יכול לחוש את המדיום החיצוני. נימים הן דוגמה מעניינת במיוחד של חיישן WGM מבוסס. בעוד WGMs נימים, גלילי יכול להיוצר סביב החתך העגול, דומה למקרה לכדור. אם קיר הנימים דק מאוד, חלק מהשדה האלקטרומגנטי משתרע לתוך ערוץ הנימים (האיור 1b). לפיכך, נימים יכולות להיות חיישן microfluidic לanalytes הוזרק לתוך הערוץ. זה באס של מבצע של טבעת נוזלי ליבה האופטית מהוד (LCORR) 11. LCORRs להסתמך על הצימוד החולף של אור ממקור ליזר דיוק tuneable לחקור את WGMs. היבט חשוב של LCORR הוא שקירות הנימים חייבים להיות רזים (~ 1 מיקרומטר) כדי להבטיח שאת הדגימות במצב בינונית הערוץ. זה מציב כמה קשיים בייצורם וגורם להם להיות שביר מכאני. בעבודה שלנו, פתחו מבנה חלופי שאנו מכנים microcavity ליבת ניאון (FCM). 12,13 כדי ליצור FCM, אנו מעייל קירות הערוץ של נימים עם fluorophore גבוה שבירת מדד (במיוחד, שכבה נקודתי התחמוצת סיליקון משובץ קוונטים). המדד הגבוה של הסרט נדרש להגביל את הקרינה הנפלטת, ובכך לבנות את WGMs (האיור 1 ג). בניגוד לLCORR, בFCM המצבים להופיע כmaxima חד בספקטרום נפלט פלואורסצנטי. העובי שלסרט הוא חשוב וקריטי, ואם הוא סמיך מדי WGM לא לטעום את המדיום בערוץ הנימים, ואם הוא דק מדי כליאה האופטית אבד וWGMs להיות חלש. לפיכך, הייצור של FCM הוא תהליך קשה, שדורש הכנה מדוקדקת. זה הנושא המרכזי של המאמר הנוכחי.

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> טבלה של חומרים </td><td> חברה </td><td> קטלוג # </td><td> תגובות </td></tr><tr><td> סיליקה microcapillaries </td><td></td><td></td><td></td></tr><tr><td> צינור גמיש microbore </td><td></td><td></td><td> פוליאתילן, tygon, וכו &#39; </td></tr><tr><td> דביק </td><td> קמע, נועה ארצות הצפון </td><td></td><td></td></tr><tr><td> HSQ מומס בMIBK </td><td></td><td></td><td> למשל., FOX-15 </td></tr><tr><td> מתנול </td><td></td><td></td><td></td></tr><tr><td> אתנול </td><td></td><td></td><td></td></tr><tr><td> מים מזוקקים </td><td></td><td></td><td></td></tr></tbody></table> טבלת 1. רשימה של חומרים המשמשים.

synthesis and operation of fluorescent-core microcavities for refractometric sensing

נייר זה דן בחיישני ליבת ניאון microcavity מבוסס שיכול לפעול בהתקנת ניתוח microfluidic. מבנים אלה מבוססים על היווצרות קוונטים-dot ציפוי ניאון (QD) על פני השטח של ערוץ microcapillary הקונבנציונלי. QDs הסיליקון הם אטרקטיבי במיוחד ליישום זה, בשל בחלקו לרעילות הזניחה בהשוואה לII-VI וQDs המתחם II-VI, אשר נשלטים חומרי תחיקה במדינות רבות. בעוד ספקטרום פליטת ההרכב הוא רחב וחסר ייחוד, סרט Si-QD על קיר הערוץ של תכונות נימי סט של פסגות חדות, צרות בספקטרום הקרינה, המקבילה לתהודות אלקטרומגנטיים לאור הלכוד בתוך הסרט. גל השיא של תהודות אלה רגיש למדיום החיצוני, ובכך מאפשר למכשיר לתפקד כחיישן refractometric בי QDs לא בא במגע פיזי עם את אנליטי. הניסויישיטות הקשורות לייצור של microcapillaries ניאון הליבות הם דנו בפירוט, כמו גם את שיטות הניתוח. לבסוף, השוואה נעשית בין המבנים הללו ואת תהודת הטבעת האופטית חקר נרחבת יותר נוזלי הליבה, במונחים של יכולות חישת microfluidic.

סטיות קטנות בהליך ייצור הנימים יכולות להוביל לשינויים משמעותיים בשיעור הצלחת המדגם. באיור 5 (מודעה), אנו מציגים דוגמאות מייצגות של נימים נכשלו, כמו גם מוצלחת. ככלל, האינדיקציה ויזואלית של מדגם מוצלח היא פלואורסצנטי אדום בשילוב עם עצמה גבוהה בקירות הנימים ופנ...

Watch this Scientific Journal Video about Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing at JoVE.com

Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

חיישני microcavity פלורסנט ליבות להעסיק גבוה ציפוי מדד קוונטים-dot בערוץ של סיליקה microcapillaries. שינויים במקדם השביר של נוזלים נשאבים לתוך סיבת ערוץ נימי המשמרות בספקטרום פלואורסצנטי microcavity שניתן להשתמש בו כדי לנתח את מדיום הערוץ.

סינתזה והפעלה של microcavities פלורסנט ליבות לחישת Refractometric

This paper discusses  fluorescent core microcavity-based sensors that can operate in a microfluidic  analysis setup. These structures are based on the ...

synthesis-operation-fluorescent-core-microcavities-for-refractometric

Research

JoVE Journal

Engineering

12.8K Views.  University of Alberta. חיישני microcavity פלורסנט ליבות להעסיק גבוה ציפוי מדד קוונטים-dot בערוץ של סיליקה microcapillaries. שינויים במקדם השביר של נוזלים נשאבים לתוך סיבת ערוץ נימי המשמרות בספקטרום פלואורסצנטי microcavity שניתן להשתמש בו כדי לנתח את מדיום הערוץ.

Video: Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor

Refractive index (RI) sensing is a powerful noninvasive and label-free sensing technique for the identification, detection and monitoring of microfluidic samples with a wide range of possible sensor designs such as interferometers and resonators 1,2. Most of the existing RI sensing applications focus on biological materials in aqueous solutions in visible and IR frequencies, such as DNA hybridization and genome sequencing. At terahertz frequencies, applications include quality control, monitoring of industrial processes and sensing and detection applications involving nonpolar materials.
Several potential designs for refractive index sensors in the terahertz regime exist, including photonic crystal waveguides 3, asymmetric split-ring resonators 4, and photonic band gap structures integrated into parallel-plate waveguides 5. Many of these designs are based on optical resonators such as rings or cavities. The resonant frequencies of these structures are dependent on the refractive index of the material in or around the resonator. By monitoring the shifts in resonant frequency the refractive index of a sample can be accurately measured and this in turn can be used to identify a material, monitor contamination or dilution, etc.
The sensor design we use here is based on a simple parallel-plate waveguide 6,7. A rectangular groove machined into one face acts as a resonant cavity (Figures 1 and 2). When terahertz radiation is coupled into the waveguide and propagates in the lowest-order transverse-electric (TE1) mode, the result is a single strong resonant feature with a tunable resonant frequency that is dependent on the geometry of the groove 6,8. This groove can be filled with nonpolar liquid microfluidic samples which cause a shift in the observed resonant frequency that depends on the amount of liquid in the groove and its refractive index 9.
Our technique has an advantage over other terahertz techniques in its simplicity, both in fabrication and implementation, since the procedure can be accomplished with standard laboratory equipment without the need for a clean room or any special fabrication or experimental techniques. It can also be easily expanded to multichannel operation by the incorporation of multiple grooves 10. In this video we will describe our complete experimental procedure, from the design of the sensor to the data analysis and determination of the sample refractive index.

The procedure for implementing a refractive index sensor for terahertz frequencies based on a grooved parallel-plate waveguide geometry is described here. The method yields a measurement of the refractive index of a small volume of liquid through monitoring of the shift in the resonant frequency of the waveguide structure

חישת Terahertz Microfluidic באמצעות חיישן מוליך גל מקביל צלחת

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

Fabrication, Operation and Flow Visualization in Surface-acoustic-wave-driven Acoustic-counterflow Microfluidics

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we present the fabrication protocol for a multilayered SAW acoustic counterflow device. The device is fabricated starting from a lithium niobate (LN) substrate onto which two interdigital transducers (IDTs) and appropriate markers are patterned. A polydimethylsiloxane (PDMS) channel cast on an SU8 master mold is finally bonded on the patterned substrate. Following the fabrication procedure, we show the techniques that allow the characterization and operation of the acoustic counterflow device in order to pump fluids through the PDMS channel grid. We finally present the procedure to visualize liquid flow in the channels. The protocol is used to show on-chip fluid pumping under different flow regimes such as laminar flow and more complicated dynamics characterized by vortices and particle accumulation domains.

In this video we first describe fabrication and operation procedures of a surface acoustic wave (SAW) acoustic counterflow device. We then demonstrate an experimental setup that allows for both qualitative flow visualization and quantitative analysis of complex flows within the SAW pumping device.

ייצור, תפעול ויזואליזציה זרימה במיקרופלואידיקה אקוסטית-נגדית Surface--מונע גל אקוסטי

Surface acoustic waves (SAWs) can be used to drive liquids in portable microfluidic chips via the acoustic counterflow phenomenon. In this video we ...

Fabrication and Operation of a Nano-Optical Conveyor Belt

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological and physical sciences over the past few decades. The progress made in this field invites further study of even smaller systems and at a larger scale, with tools that could be distributed more easily and made more widely available. Unfortunately, the fundamental laws of diffraction limit the minimum size of the focal spot of a laser beam, which makes particles smaller than a half-wavelength in diameter hard to trap and generally prevents an operator from discriminating between particles which are closer together than one half-wavelength. This precludes the optical manipulation of many closely-spaced nanoparticles and&#160;limits the&#160;resolution of optical-mechanical systems. Furthermore, manipulation using focused beams requires beam-forming or steering optics, which can be very bulky and expensive. To address these limitations in the system scalability of conventional optical trapping our lab has devised an alternative technique which utilizes near-field optics to move particles across a chip. Instead of focusing laser beams in the far-field, the optical near field of plasmonic resonators produces the necessary local optical intensity enhancement to overcome the restrictions of diffraction and manipulate particles at higher resolution. Closely-spaced resonators produce strong optical traps which can be addressed to mediate the hand-off of particles from one to the next in a conveyor-belt-like fashion. Here, we describe how to design and produce a conveyor belt using a gold surface patterned with plasmonic C-shaped resonators and how to operate it with polarized laser light to achieve super-resolution nanoparticle manipulation and transport. The nano-optical conveyor belt chip can be produced using lithography techniques and easily packaged and distributed.

The scalability and resolution of conventional optical manipulation techniques are limited by diffraction. We circumvent the diffraction limit and describe a method of optically transporting nanoparticles across a chip using a gold surface patterned with a path of closely spaced C-shaped plasmonic resonators.

ייצור ותפעול של מסוע ננו-אופטי

The technique of using focused laser beams to trap and exert forces on small particles has enabled many pivotal discoveries in the nanoscale biological ...

Fabrication and Operation of Acoustofluidic Devices Supporting Bulk Acoustic Standing Waves for Sheathless Focusing of Particles

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must be smaller than the incident wavelength of sound and the width of the fluidic channels are typically tens to hundreds of micrometers across, acoustofluidic devices typically use ultrasonic waves generated from a piezoelectric transducer pulsating at high frequencies (in the megahertz range). At characteristic frequencies that depend on the geometry of the device, it is possible to induce the formation of standing waves that can focus particles along desired fluidic streamlines within a bulk flow. Here, we describe a method for the fabrication of acoustophoretic devices from common materials and clean room equipment. We show representative results for the focusing of particles with positive or negative acoustic contrast factors, which move towards the pressure nodes or antinodes of the standing waves, respectively. These devices offer enormous practical utility for precisely positioning large numbers of microscopic entities (e.g., cells) in stationary or flowing fluids for applications ranging from cytometry to assembly.

Acoustofluidic devices use ultrasonic waves within microfluidic channels to manipulate, concentrate and isolate suspended micro and nanoscopic entities. This protocol describes the fabrication and operation of such a device supporting bulk acoustic standing waves to focus particles in a central streamline without the aid of sheath fluids.

ייצור והפעלה של Acoustofluidic התקנים התומכים גלים אקוסטיים המתמדת בכמות גדולה עבור Sheathless התמקדות של חלקיקים

Acoustophoresis refers to the displacement of suspended objects in response to directional forces from sound energy. Given that the suspended objects must ...

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors.

A protocol for the colloidal synthesis of silver nanocubes and fabrication of plasmonic nanoscale patch antennas with sub-10 nm gaps is presented.

סינתזה קולואיד של אנטנות Nanopatch עבור יישומים plasmonics ו Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

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.

חוטים לייזר הפמטו-שנייה לשימוש משנה-Diffraction-מוגבלת וחישה מרחוק

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

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing

We present a protocol for performing gas spectroscopy using infrared degenerated four-wave mixing (IR-DFWM), for the quantitative detection of gas species in the ppm-to-single-percent range. The main purpose of the method is the spatially resolved detection of low-concentration species, which have no transitions in the visible or near-IR spectral range that could be used for detection. IR-DFWM is a nonintrusive method, which is a great advantage in combustion research, as inserting a probe into a flame can change it drastically. The IR-DFWM is combined with upconversion detection. This detection scheme uses sum-frequency generation to move the IR-DFWM signal from the mid-IR to the near-IR region, to take advantage of the superior noise characteristics of silicon-based detectors. This process also rejects most of the thermal background radiation. The focus of the protocol presented here is on the proper alignment of the IR-DFWM optics and on how to align an intracavity upconversion detection system.

Here, we present a protocol to perform sensitive, spatially resolved gas spectroscopy in the mid-infrared region, using degenerate four-wave mixing combined with upconversion detection.

אינפרא-אדום מנוונת ארבעה גלים ערבוב עם זיהוי Upconversion עבור גז כמותיים חישה

We present a protocol for performing gas spectroscopy using infrared degenerated four-wave mixing (IR-DFWM), for the quantitative detection of gas species ...

Synthesis, Functionalization, and Characterization of Fusogenic Porous Silicon Nanoparticles for Oligonucleotide Delivery

With the advent of gene therapy, the development of an effective in vivo nucleotide-payload delivery system has become of parallel import. Fusogenic porous silicon nanoparticles (F-pSiNPs) have recently demonstrated high in vivo gene silencing efficacy due to its high oligonucleotide loading capacity and unique cellular uptake pathway that avoids endocytosis. The synthesis of F-pSiNPs is a multi-step process that includes: (1) loading and sealing of oligonucleotide payloads in the silicon pores; (2) simultaneous coating and sizing of fusogenic lipids around the porous silicon cores; and (3) conjugation of targeting peptides and washing to remove excess oligonucleotide, silicon debris, and peptide. The particle&#8217;s size uniformity is characterized by dynamic light scattering, and its core-shell structure may be verified by transmission electron microscopy. The fusogenic uptake is validated by loading a lipophilic dye, 1,1&#39;-dioctadecyl-3,3,3&#39;,3&#39;-tetramethylindocarbocyanine perchlorate (DiI), into the fusogenic lipid bilayer and treating it to cells in vitro to observe for plasma membrane staining versus endocytic localizations. The targeting and in vivo gene silencing efficacies were previously quantified in a mouse model of Staphylococcus aureus pneumonia, in which the targeting peptide is expected to help the F-pSiNPs to home to the site of infection. Beyond its application in S. aureus infection, the F-pSiNP system may be used to deliver any oligonucleotide for gene therapy of a wide range of diseases, including viral infections, cancer, and autoimmune diseases.

We demonstrate the synthesis of fusogenic porous silicon nanoparticles for effective in vitro and in vivo oligonucleotide delivery. Porous silicon nanoparticles are loaded with siRNA to form the core, which is coated by fusogenic lipids through extrusion to form the shell. Targeting moiety functionalization and particle characterization are included.

סינתזה Functionalization, איפיון חלקיקים הסיליקון הנקבובי Fusogenic למסירה Oligonucleotide

With the advent of gene therapy, the development of an effective in vivo nucleotide-payload delivery system has become of parallel import. Fusogenic ...

Robotic Sensing and Stimuli Provision for Guided Plant Growth

Robot systems are actively researched for manipulation of natural plants, typically restricted to agricultural automation activities such as harvest, irrigation, and mechanical weed control. Extending this research, we introduce here a novel methodology to manipulate the directional growth of plants via their natural mechanisms for signaling and hormone distribution. An effective methodology of robotic stimuli provision can open up possibilities for new experimentation with later developmental phases in plants, or for new biotechnology applications such as shaping plants for green walls. Interaction with plants presents several robotic challenges, including short-range sensing of small and variable plant organs, and the controlled actuation of plant responses that are impacted by the environment in addition to the provided stimuli. In order to steer plant growth, we develop a group of immobile robots with sensors to detect the proximity of growing tips, and with diodes to provide light stimuli that actuate phototropism. The robots are tested with the climbing common bean, Phaseolus vulgaris, in experiments having durations up to five weeks in a controlled environment. With robots sequentially emitting blue light-peak emission at wavelength 465 nm-plant growth is successfully steered through successive binary decisions along mechanical supports to reach target positions. Growth patterns are tested in a setup up to 180 cm in height, with plant stems grown up to roughly 250 cm in cumulative length over a period of approximately seven weeks. The robots coordinate themselves and operate fully autonomously. They detect approaching plant tips by infrared proximity sensors and communicate via radio to switch between blue light stimuli and dormant status, as required. Overall, the obtained results support the effectiveness of combining robot and plant experiment methodologies, for the study of potentially complex interactions between natural and engineered autonomous systems.

Distributed robot nodes provide sequences of blue light stimuli to steer the growth trajectories of climbing plants. By activating natural phototropism, the robots guide the plants through binary left-right decisions, growing them into predefined patterns that by contrast are not possible when the robots are dormant.

הקצאת חישה רובוטית וגירויים לגידול הצמח המודרך

Robot systems are actively researched for manipulation of natural plants, typically restricted to agricultural automation activities such as harvest, ...

Operation of the Collaborative Composite Manufacturing (CCM) System

The automated tape placement and the automated fiber placement (AFP) machines provide a safer working environment and reduce the labor intensity of workers than the traditional manual fiber placement does. Thus, the production accuracy, repeatability and efficiency of composite manufacturing are significantly improved. However, the current AFP systems can only produce the composite components with large open surface or simple revolution parts, which cannot meet the growing interest in small complex or closed structures from industry.
In this research, by employing a 1-degree of freedom (DoF) rotational stage, a 6-RSS parallel robot, and a 6-DoF serial robot, the dexterity of the AFP system can be significantly improved for manufacturing complex composite parts. The rotational stage mounted on the parallel robot is utilized to hold the mandrel and the serial robot carries the placement head to mimic two human hands that have enough dexterity to lay the fiber to the mandrel with complex contour.
Although the CCM system increases the flexibility of composite manufacturing, it is quite time-consuming or even impossible to generate the feasible off-line path, which ensures uniform lay-up of subsequent fibers considering the constraints like singularities, collisions between the fiber placement head and mandrel, smooth fiber direction change and keeping the fiber placement head along the norm of the part&#39;s surface, etc. Moreover, due to the existing positioning error of the robots, the on-line path correction is needed. Therefore, the on-line pose correction algorithm is proposed to correct the paths of both parallel and serial robots, and to keep the relative path between the two robots unchanged through the visual feedback when the constraint or singularity problems in the off-line path planning occur. The experimental results demonstrate the designed CCM system can fulfill the movement needed for manufacturing a composite structure with Y-shape.

Operation of the Collaborative Composite Manufacturing CCM System

A collaborative composite manufacturing system is developed for robotic lay-up of composite laminates using the prepreg tape. The proposed system allows the production of composite laminates with high levels of geometrical complexity. The issues in the path planning, coordination of the robots and control are addressed in the proposed method.

מבצע של מערכת הייצור המשולב שיתופי (CCM)

The automated tape placement and the automated fiber placement (AFP) machines provide a safer working environment and reduce the labor intensity of ...