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Proceedings ArticleDOI

Heating of samples by acoustic microagitation for improving reaction of biological fluids

TL;DR: In this paper, an acoustic microagitator for biological fluids analysis is described, where a piezoelectric transducer is used to heat the samples, improving the reaction of fluids that benefit from that effect.
Abstract: This article describes an acoustic microagitator for being used in biological fluids analysis. It is known that a piezoelectric transducer, with its vibration, can be used for mixing fluids. However, in this case, the piezoelectric transducer is also used to heat the samples, improving the reaction of fluids that benefit from that effect. The piezoelectric transducer is fabricated from a poly(vinylidene fluoride) polymer, in the beta phase (β-PVDF). This concept is demonstrated theoretically and by measuring the temperature profile in a regular 1 cm optical lightpath glass cuvette, using capillary thermocouples. This system can further be included in a lab-on-a-chip device, acting as a microreactor, for clinical diagnosis.
Citations
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Journal ArticleDOI
TL;DR: Work supported by FEDER funds through the Eixo I do Programa======Operacional Fatores de Competitividade (POFC) QREN, project reference PTDC/======EBB•EBI/120334/2010 as discussed by the authors.
Abstract: Work supported by FEDER funds through the Eixo I do Programa Operacional Fatores de Competitividade (POFC) QREN, project reference COMPETE: FCOMP‐01‐0124‐FEDER‐020241 and by FCTFundacao para a Ciencia e a Tecnologia, project reference PTDC/ EBB‐EBI/120334/2010. Susana O. Catarino thanks the FCT for the SFRH/BD/61767/2009 grant.

14 citations

Journal ArticleDOI
26 Nov 2012
TL;DR: In this article, the authors describe the modelling of heat transfer produced by the acoustic streaming phenomenon, generated through a piezoelectric transducer in a microagitator.
Abstract: The present work describes the modelling of heat transfer produced by the acoustic streaming phenomenon, generated through a piezoelectric transducer in a microagitator. Besides the fluids mixing, this phenomenon also promotes the fluids heating. The numerical approach used in this work comprises three main groups of equations: the piezoelectric, the compressible Navier-Stokes, and the heat transfer equations. It was concluded that the heat transfer due to the acoustic wave propagation, without other external heat sources, is not sufficient to increase significantly the fluid temperature.

6 citations

22 Aug 2011
TL;DR: Work supported by FEDER funds through the "Programa Operacional Factores de======Competitividade - COMPETE" and by national======fundings by FCT- Fundacao para a Ciencia e a======Tecnologia project reference======PTDC/BIO/70017/2006 as discussed by the authors.
Abstract: Work supported by FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETE" and by national funds by FCT- Fundacao para a Ciencia e a Tecnologia project reference PTDC/BIO/70017/2006. S. O. Catarino thanks the FCT for the SFRH/BD/61767/2009 grant

3 citations


Cites background from "Heating of samples by acoustic micr..."

  • ...These microfluidic systems allow the immediate detection and quantification of a wide range of biomolecules in biological fluids [3, 4], presenting as main advantages the small size and low power consumption for being used as reliable point-of-care devices....

    [...]

22 Jul 2012
TL;DR: Work supported by FEDER funds through the "Programa Operacional Factores de Competitividade - COMPETE" and by national funds by FCT- Fundacao para a Ciencia e a Tecnologia project reference PTDC/BIO/70017/2006 as discussed by the authors.
Abstract: Work supported by FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETE" and by national funds by FCT- Fundacao para a Ciencia e a Tecnologia project reference PTDC/BIO/70017/2006. S. O. Catarino thanks the FCT for the SFRH/BD/61767/2009 grant.

2 citations

Proceedings ArticleDOI
01 Mar 2011
TL;DR: In this article, the authors focused on lab-on-a-chip devices for clinical applications, with on-chip integration of electronic circuits, optical filters and (bio)sensors.
Abstract: The research team is focused on lab-on-a-chip devices for clinical applications, with on-chip integration of electronic circuits, optical filters and (bio)sensors. An example of the work is a lab-on-a-chip where acoustic streaming technique is used to promote the mixing and the pumping of the fluids inside microchannels. The transducer that generates the acoustic streaming is based on a piezoelectric polymer, processed to be functionally graded for, in conjunction with the signal applied to the transducers, being able to control the movement and heating of the fluids. A highly selective optical interference filter co-integrated in CMOS allows the use of only a white light source when spectrophotometry is used as the detection technique, resulting in an actually portable device.

2 citations


Cites background from "Heating of samples by acoustic micr..."

  • ...It was experimentally proved that an acoustic microagitator based on a PVDF piezoelectric transducer, besides mixing, increases the fluids temperature [ 6 ]....

    [...]

References
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Journal ArticleDOI
TL;DR: In this article, the authors present a review of the book.http://www.reviewreviews.com/reviews/book-reviews-of-the-book
Abstract: Review

2,157 citations

Journal ArticleDOI
TL;DR: This second part of the review of microfluidic system preparation will cover a number of standard operations as well as some biological applications of micro total analysis systems.
Abstract: After having reviewed some aspects of microfluidic system preparation in the first part (1), in this second part of the review we will cover a number of standard operations (namely: sample preparation, sample injection, sample manipulation, reaction, separation, and detection) as well as some biological applications of micro total analysis systems (namely: cell culture, polymerase chain reaction, DNA separation, DNA sequencing, and clinical diagnostics). As previously, we will include papers issued from different scientific journals as well as useful abstracts from three conference proceedings: MEMS, Transducers, and μTAS. In this second part, we do not include the period covered by the history section (1975-1997) from part 1 but try to cover the relevant examples of the literature published between January 1998 and March 2002. We briefly describe articles that struck us as needing special attention, while more “standard” papers are dutifully reported in groups of interest. An article might be included in more than one section, depending on the ideas developed in it.

1,541 citations

Book
01 Jan 2001
TL;DR: In this article, the authors present a comprehensive overview of the field of electroactive polymer gels, ionomeric polymer-metal composites, carbon nanotube actuators, and more.
Abstract: In concept and execution, this book covers the field of EAP with careful attention to all its key aspects and full infrastructure, including the available materials, analytical models, processing techniques, and characterization methods. In this second edition the reader is brought current on promising advances in EAP that have occurred in electric EAP, electroactive polymer gels, ionomeric polymer-metal composites, carbon nanotube actuators, and more.

1,527 citations

Journal ArticleDOI
TL;DR: This work presents an alternative paradigm--a fully integrated and reconfigurable droplet-based "digital" microfluidic lab-on-a-chip for clinical diagnostics on human physiological fluids, and demonstrates reliable and repeatable high-speed transport of microdroplets.
Abstract: Clinical diagnostics is one of the most promising applications for microfluidic lab-on-a-chip systems, especially in a point-of-care setting. Conventional microfluidic devices are usually based on continuous-flow in microchannels, and offer little flexibility in terms of reconfigurability and scalability. Handling of real physiological samples has also been a major challenge in these devices. We present an alternative paradigm—a fully integrated and reconfigurable droplet-based “digital” microfluidic lab-on-a-chip for clinical diagnostics on human physiological fluids. The microdroplets, which act as solution-phase reaction chambers, are manipulated using the electrowetting effect. Reliable and repeatable high-speed transport of microdroplets of human whole blood, serum, plasma, urine, saliva, sweat and tear, is demonstrated to establish the basic compatibility of these physiological fluids with the electrowetting platform. We further performed a colorimetric enzymatic glucose assay on serum, plasma, urine, and saliva, to show the feasibility of performing bioassays on real samples in our system. The concentrations obtained compare well with those obtained using a reference method, except for urine, where there is a significant difference due to interference by uric acid. A lab-on-a-chip architecture, integrating previously developed digital microfluidic components, is proposed for integrated and automated analysis of multiple analytes on a monolithic device. The lab-on-a-chip integrates sample injection, on-chip reservoirs, droplet formation structures, fluidic pathways, mixing areas and optical detection sites, on the same substrate. The pipelined operation of two glucose assays is shown on a prototype digital microfluidic lab-on-chip, as a proof-of-concept.

1,124 citations