Ingegneria dell'Informazione

Transmitting Information with Microfluidic SystemsAndrea Biral, Davide Zordan, Andrea ZanellaICC2015 8-12 June 2015, London, UKzanella@dei.unipd.it

1OutlineMicrofluidics and its applicationsLab on a ChipResearch interestsOur contributionTransmitting information with microfluidic circuitsPAM-like codingExperimental setupResultsConclusion2Microfluidics3Microfluidics is both a science and a technology that deals with the control of small amounts of fluids flowing through microchannels

Droplet microfluidicsDroplets (dispersed phase) encapsulating samples and reagents are dispersed into an immiscibile fluid (continuous phase)

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Boolean microfluidicM Prakash, N Gershenfeld - Science, 2007 Microfluidic bubble logic

De Leo et al. TCOM 2013 Communications and Switching in Microfluidic Systems: Pure Hydrodynamic Control for Networking Labs-on-a-Chip 4Our contributionAdd communication capabilities in microfluidic systemsTransmit information in a microfluidic channel by means of a PAM like modulationUse droplet length/interdistance to code the informationEvaluate system performance on a real case scenario

5Droplets generation By changing input parameters, you can control (average) droplets length and spacing, but NOT independently!

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(volumetric flow rate Qd)(volumetric flow rate Qc)Constant (~1)

Modulation Bit string 00011011

PAM symbols 0 1 2 3

Droplet length

Dispersed phase flow0.5 11.5 2 [l/min]

Continuous phase flow 5 [l/min]

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Experimental setup8

Continuous Phase(Hexadecane + Span80)Dispersed Phase(Water + Glycerol)

Frame processing9

Camera frame

Binary image

Lowpass Wiener filterMedian filter

Connected components identification

Droplet lengths

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We assume that the length(interdistance) can be modeled as a Gaussian RV

The assumption can be validated comparing the empirical and theoretical CDFs

Droplets length distribution 11

Symbols PDFs

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Error probability13

Assuming equally likely symbolsDroplet-length PAMInter-droplet distance PAMWrapping upThis work:investigated the feasibility of extending communication concept to microfluidicsimplemented basic modulation technique based on length/interdistance evaluated system performance with experimental dataBoth droplet length and inter-droplet distance can carry information bitsInter-distance is generally preferable BUT, in complex network, it can vary as droplets stream along the channels See Biral & Zanella, NanoComNet 201314Looking forward15

Transient characterizationTime to change modulated symbolRelated to symbol periodDepends on the distance between symbols symbol-dependent transmission ratemore sophisticated modulationsCombining length and distanceUsing other circuits to dynamically change droplet inter-distanceconsider other performance indexesthroughput, delay, energy consumption

Transmitting Information with Microfluidic SystemsAndrea Biral, Davide Zordan, Andrea Zanella

Any questions?16Microfluidic application:Lab on a Chip

17 thinXXS MicrotechnologyMicrofluidic research:Tunable filters, Optical Switches,

Switching Fiber-Optic Circuits with Microscopic Bubbles John Uebbing, Agilent Technologies

Chin, L. K.; Liu, A.Q.; Zhang, J.B.; Lim, C. S.; Soh, Y. C., "An on-chip liquid tunable grating using multiphase droplet microfluidics,"Applied Physics Letters, vol.93, no.16, pp.164107,164107-3, Oct 200818