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MF20

Powerful Work: Microfluidic Paper Fuel Cells

Greg Thiessen
1 May 2014

Senior Research Fellow, Juan Pablo Esquivel, and his colleagues in Barcelona, Spain were recently published in Energy & Environmental Science for their work on microfluidic paper fuel cells [1]. This work details the development of a fuel cell consisting of methanol and KOH. By harnessing the capillary flow of porous membranes, the need for external pumps to supply reactants is eliminated. The electrolyte (KOH) and fuel (methanol) are stored within a lateral flow device such that the addition of water generates power. The ability to use the sample, such as blood, to generate power is incredibly beneficial and exciting. I’m not the only one to get excited about it either. The work was highlighted in the March edition of Science Magazine in the Editor’s Choice section [2], as well as in Chemistry World. This design can be used to power the detection of analyte, replacing the need for button-cell batteries. This truly is powerful work.

Schematic of a paper-based microfluidic fuel cell design. Figure courtesy of J.P. Esquivel.
  1. Esquivel, J.P., et al., Microfluidic fuel cells on paper: meeting the power needs of next generation lateral flow devices. Energy & Environmental Science, 2014.
  2. Fahrenkamp-Uppenbrink, J., Paper Power. Science, 2014. 343(6176): p. 1179.

Paper-Based Microfluidics Goes Digital

Karen Keniston
5 February 2014

Due to the passive nature of traditional paper-based microfluidic devices, high precision control of certain parts of multi-step assays can be difficult to acheive.  Researchers R. Fobel et al. at the University of Toronto recently published an article in Advanced Materials reporting the invention of a digital paper-based microfluidic device with high precision control of multistep processes on paper.

Digital microfluidics (DMF) is a technology in which nano-to-microliter sized drops are manipulated on an array of electrodes using electric fields. The electrostatic forces can move, split, merge, and dispense drops to and from reservoirs within a device without the use of active pumps or moving parts. Paper-based DMF devices are fabricated by inkjet printing silver electrodes and reservoirs onto smooth paper surfaces. To test the ability of the novel device to perform a multistep process, the group used one of the chips to perform a serial dilution and create a calibration curve for the chemiliuminescence assay of horseradish peroxidase (HRP) mixed with luminol and hydrogen peroxide. Overall, very interesting applications may come from combining these methods with the traditional paper-based diagnostic assay, especially in steps which would be difficult to perform with solely capillary-driven flow. 

Demonstration of digital microfluidics on a paper-based device. Fobel, R., Kirby, A. E., Ng, A. H. C., Farnood, R. R. and Wheeler, A. R. (2014), Paper Microfluidics Goes Digital. Adv. Mater.. doi: 10.1002/adma.201305168 © 2014 Advanced Materials.

 

 

Seeking Blog Contributors!

Carly Holstein
21 October 2013

In an effort to fully represent the Microfluidics 2.0 community, we are seeking blog posts from guest contributors. If you are a member of the Microfluidics 2.0 community and would like to write a blog post about your work, other MF2.0 work you find interesting, or other topics relevant to the MF2.0 world, please let us know! If interested, send us an email (yagerlab at gmail dot com) with your name, affiliation, and a brief description of the topic you'd like to write about. Looking forward to your contributions!

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Dissolvable Sugar Barriers for Fluidic Time Delays

Carly Holstein
2 July 2013

Professors Barry Lutz, Elain Fu, Paul Yager, and colleagues have published their work on sugar-based time delays for paper devices in the most recent issue of Lab on a Chip. This work describes the use of dissolvable sugar barriers to create and control fluidic time delays in paper microfluidic devices. This technique can be used to program multi-step assays that enable automated, easy-to-use paper diagnostic tests. What a “sweet” example of MF2.0!

Illustration of the sugar barrier concept and the use of these dissolvable barriers to create fluidic time delays. Lutz et al., "Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics," Lab on a Chip 13: 2840-2847 (2013). © Royal Society of Chemistry 2013

Apply Now: Gordon Research Conference on Microfluidics

Carly Holstein
18 March 2013

We are excited to help spread the word that applications to this year's Gordon Research Conference on the Physics & Chemistry of Microfluidics are currently being accepted! This GRC is a must-attend for anyone in the Microfluidics 2.0 field, as the focus of the conference is on "Challenges, Adcances, and New Technologies for Diagnostics." The co-chairs of the conference, Drs. James Landers and Paul Yager, have selected a wonderful line-up of speakers for talks in the following session areas:

  • Fluidic control
  • Paper microfluidics
  • Microfluidic acoustics
  • Centrifugally-driven microfluidics
  • Diagnostics
  • Commericalization of microfluidic technology
  • Next-generation sequencing

This GRC will be held June 9-14, 2013 at the Renaissance Tuscany Il Ciocco Resort in Lucca (Barga), Italy. Applications are due by May 12, 2013, but applications are reviewed on a first-come, first-served basis, so early applications are encouraged!

Also, if you are a graduate student or post-doc, please also consider attending the corresponding Gordon Research Seminar, taking place directly prior to the GRC (June 8-9, 2013). The theme of this GRS is also very fitting for the MF20 community: "From Bench-to-Beside: From Diagnosis through Treatment." Applications are due by May 11, 2013, but again, early applications are encouraged! Please note that graduate students and post-docs can (and should) also apply to the GRC.

In case this exciting scientific program is not enticing enough, perhaps the beautiful venue can do the talking:

Patio of the Renaissance Tuscany Il Ciocco Resort, where the GRC/GRS will be held. Photo courtesy of the Gordon Research Conferences © 2013.

Hope to see you there!

Weaving Our Way Towards Low-Cost Disease Diagnostics

Bhushan Toley
18 March 2013

While most ongoing development under the realm of Microfluidics 2.0 has been by using different forms of paper for wicking fluids, Dhananjay Dendukuri, CEO and co-founder, Achira Labs (Bangalore, India), decided to utilize silk instead of paper to develop low-cost powerless microfluidic devices. In a land adorned by women clad in 6-yard woven sheets of silk – the famous Indian Sari – silk yarn fabrication is a well-established industry. Dhananjay applied the weaving principles of the warp and the weft to design the proprietary “Fab-Chip” platform. Silk yarns with different properties were selected, pretreated with chemical agents, and handloom-woven into a fabric chip. Wetting and non-wetting yarns were weaved in a desired pattern to define flow channels on the chip. What’s more, the yarn twist frequency and coverage area could be modified to modify the rate of fluid wicking through these chips. This technology was described in their Lab on a Chip publication in July 2011. The technology makes use of the existing silk manufacturing infrastructure to develop products for point-of-care diagnostics – a strategy that will enable low-cost manufacturing as well as create local employment opportunities. Microfluidics 2.0 continues to present paradigm-shifting opportunities…

Images of the silk-based "Fab-Chip" diagnostic platform from Achira Labs. http://www.achiralabs.com/technology.html, accessed 18 March 2013. © Copyrights 2011, Achira.