application note - Dolomite Microfluidics

The Dolomite Centre LtdUnit 1, Anglian Business Park, Orchard Road,Royston, Hertfordshire, SG8 5TW, UKT: +44 (0)1763 242491F: +44 (0)1763 246125E: sales@dolomite-microfluidics.comW: www.dolomite-microfluidics.comDolomite Microfluidics – North America OfficeBlacktrace Inc, 29 Albion PlaceCharlestown, MA 02129, USAC: 617 803 6655T: 617 848 1121F: 617 500 0136E: salesus@dolomite-microfluidics.comMitos P-Pump DropletMonodispersityA comparison of the size consistency of droplets formedby the Mitos P-Pump and a market leading syringe pumpapplication notepageAbout Monodisperse Droplet Formation 2Monodispersity Test Set-up 2P-Pump Results 3Syringe Pump Results 4Conclusions 4The Dolomite Centre Limited Page 1 of 6

The Dolomite Centre LtdAbout Monodisperse Droplet FormationThe formation of droplets of oil-in-water or water-in-oil has a range of uses in science andindustry. Monodispersity, or size consistency, is the key to making droplet microfluidics apowerful tool for conducting accurate and repeatable experiments.Droplet Application ExampleEmulsion production in food orcosmeticsDroplets as mini chemicalreactorsDrug deliveryPerforming biochemical assaysor screensRequirement for MonodispersityConsistent texture and performance of sampleKnown chemical make-up of droplets to achieve a reactionControlled dispersion of active ingredientsAbility to keep conditions inside droplet constant andmeasure the effect of a single parameterMonodispersity Test Set-upTo enable a comparison to be made between the Mitos P-Pump pressure pumptechnology and syringe pump technology, droplets were generated using each pump typeand the droplet size distribution measured. A high speed video was captured to provide adata sample and processed using image analysis software. The droplet liquid was waterwith 10% v/v blue dye and the carrier liquid was mineral oil with 1% v/v Span 80 (Span 80is a surfactant used to increase droplet stability).3200032 F100 flow resistorF100tube A3000155 Mitos chip holder H3000024 Mitos edge connector 4-way (2x)3000301 Mitos droplet junction chip – hydrophobic3200016 Mitos P-Pump3200028 F1 flow resistorF13200016 Mitos P-PumpExperimental set-up for monodispersity test of droplets generated by the Mitos P-Pump3000155 Mitos chip holder H3000024 Mitos edge connector 4-way (2x)3000301 Mitos droplet junction chip – hydrophobicMarket leading syringe pump with 100µlsyringe (water) and 1000 µl syringe (oil)Experimental set-up for monodispersity test of droplets generated by the syringe pumpMitos P-Pump Droplet Monodispersity – application note Page 2 of 6

Droplet CountThe Dolomite Centre LtdP-Pump ResultsImage of water-in-oil droplets formed with the Mitos P-Pump and Mitos Droplet JunctionChip - Hydrophobic140Frequency Cumulative %120%120100%10080%8060%604040%2020%098 99 100 101 102 103 104Droplet diameter (μm)Histogram of water droplet size distribution with water flow rate of 1 µl/min and oil flowrate of 8.4 µl/min. Sample data obtained with Mitos P-Pump and Mitos Droplet JunctionChip – Hydrophobic and processed using image analysis software0%Measure of DistributionValueMean Droplet Diameter 99.7 µmStandard Deviation 0.6 µmMinimum Droplet Diameter 98.5 µmMaximum Droplet Diameter 102.2 µmCoefficient of Variation 0.6 %Table showing variation in droplet size – Mitos P-PumpMitos P-Pump Droplet Monodispersity – application note Page 3 of 6

Droplet CountThe Dolomite Centre LtdSyringe Pump ResultsImage of water-in-oil droplets formed with a market leading syringe pump and MitosDroplet Junction Chip - Hydrophobic605040Frequency Cumulative %120.00%100.00%80.00%30201060.00%40.00%20.00%077 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100101102Droplet diameter (μm)0.00%Histogram of water droplet size distribution with water flow rate of 1 µl/min and oil flowrate of 10 µl/min. Sample data obtained with market leading syringe pump and MitosDroplet Junction Chip – Hydrophobic and processed using image analysis softwareMeasure of DistributionValueMean Droplet Diameter 93.4 µmStandard Deviation 5.1 µmMinimum Droplet Diameter 76.8 µmMaximum Droplet Diameter 101.2 µmCoefficient of Variation 5.5 %Table showing variation in droplet size – market leading syringe pumpMitos P-Pump Droplet Monodispersity – application note Page 4 of 6

The Dolomite Centre LtdConclusionsFor generating highly monodispersed droplets, the Mitos P-Pump presents a bettersolution than a market leading syringe pump. In this test, the Mitos P-Pump provides acoefficient of variation in the droplet diameter of 0.6% compared with 5.5% for the syringepump. This illustrates that there is clear difference in flow smoothness with these twopump technologies. The precise pressure-driven pumping mechanism of the MitosP-Pump delivers liquid with a smooth and even flow, whereas even the best motor drivesand mechanics of a syringe pump have slight nonlinearities, which cause unwantedpulsation. As a result, the Mitos P-Pump technology offers optimum flow smoothness formicrofluidic applications.Mitos P-Pump Droplet Monodispersity – application note Page 5 of 6

The Dolomite Centre LtdMitos P-Pump Droplet Monodispersity – application note Page 6 of 6