Microfluidic Double Emulsion Device


    RayDrop Double Emulsion

    The RayDrop is a microfluidic double emulsion device composed of three main, fully removable parts: two inserts on each side,a center section containing a nozzle, and an outlet capillary. There are 5 standard microfluidic connections, two on the box for the continuous phase and three others: one on each insert for the core shell phase entry,and one on the collecting emulsion outlet. The droplets are produced by controlling the squeezing of the droplet phase locally generated  by the continuous phase at the entrance of the collection capillary.

    The RayDrop specific design allows for multiple liquid type emulsification within the same device with no coating needed. The device can create both single and complex emulsions.

    Raydrop Double Emulsion Device
    Main benefits
    • droplet monodispersity

      High monodispersity (CV < 2%)

    • Flexible

      Multiple applications

    • Easy

      One device, coating-free

    Features of the RayDrop Double Emulsion Device

    A unique device

    Perform double emulsions in one single device.

    A flexible device

    Droplet size from 25 µm to 450µm outer diameter. 

    Frequency of up to 5 000 Hz. 

    Water-in-oil-in-water (w/o/w) and oil-in-water-in-oil (o/w/o) within the same device.


    Exchangeable nozzles that are easy to disassemble and clean with clear. microscope visualization and the ability to connect with standard tubing and nuts.

    Surface coating not required

    As opposed to standard double emulsion devices, the Raydrop does not require any surface coating steps.

    The double emulsion device also does not require any surfactant for droplet generation.

    Developed and manufactured by Secoya

    Raydrop, a universal droplet generator based on a non embedded co flow focusing

    Check out our webinar to learn more about the RayDrop double emulsion device!

    Most commercial microfluidic droplet generators rely on the planar flow-focusing configuration implemented in polymer or glass chips. The planar geometry, however, suffers from many limitations and drawbacks, such as the need of specific coatings or the use of dedicated surfactants, depending on the fluids in play. On the contrary, and thanks to their axisymmetric geometry, glass capillary-based droplet generators are a priori not fluid-dependent. Nevertheless, they have never reached the market because their assembly requires art-dependent and not scalable fabrication techniques. Here we present a new device, called Raydrop, based on the alignment of two capillaries immersed in a pressurized chamber containing the continuous phase. The dispersed phase exits one of the capillaries through a 3D-printed nozzle, placed in front of the extraction capillary for collecting the droplets. This non-embedded implementation of an axisymmetric flow-focusing is referred to co-flow-focusing.

    In the context of a growing demand of controlled droplets in many areas, discover the Raydrop that emerges as a very robust and versatile solution easily implementable in laboratories with little experience and facilities in microfluidics.

    What you will learn:

    Introduction to droplet-based microfluidics
    Current method & technologies present on the market droplet & emulsion production
    Understand the advantages & challenges of droplet-based microfluidics
    Discover a new method for droplet and emulsion production


    Most commercially available and lab-made droplet generators are based on a flow-focusing technology implemented in rectangular microchannels fabricated by lithography and made of polydimethylsiloxane (PDMS), polymers or glass. However, this planar configuration has many limitations due to the contact between the walls of the microchannels and both phases at the junction, requiring laborious and often ephemeral wettability treatments of these walls. On the contrary, due to their axisymmetric configuration, glass capillary systems do not have this drawback since the dispersed phase is never in contact with the walls of the outer capillary.

    Therefore, The RayDrop double emulsion device relies on the alignment of two glass capillaries inside a pressurized chamber. A 3D-printed micro-nozzle is additionally connected at the tip of the injection capillary, enforcing the dripping of small droplets. This non-embedded design presents both the characteristics of a co-flow (axisymmetric geometry) and a flow-focusing (dramatic local accelerations of the continuous phase), and is thereby called non-embedded co-flow-focusing.

    Double Emulsion Device 3D-printed micro-nozzle

    TheRayDrop double emulsion chip can be used for many  applications from encapsulation of active pharmaceutical ingredients to cell and fragrance encapsulation in polymer microcapsules.

    The design is known as a “technological breakthrough” due to the following: 

    • Its ability to enable high-throughput generation of monodisperse droplets for a wide variety of fluids, due to the continuous phase  not being confined before entering the extraction capillary, and allowing for the flushing of  viscous continuous phases. 
    • The double emulsion device is “plug-and-play” because of its standard connections and the possibility to easily assemble and disassemble all parts for cleaning.

    In the context of a growing demand of controlled droplets in many areas, the Raydrop double emulsion device emerges as a robust and versatile solution, easily implementable in both laboratories with little experience and microfluidic facilities. 

    The RayDrop Double emulsion is available in three different standard configurations (Core Nozzle size-Shell Nozzle size-Extraction capillary size):

    30 µm – 70 µm – 150µm

    60 µm -120 µm – 300 µm

    90 µm -160 µm -450 µm

    Double Emulsion Device droplet
    Double Emulsion Device droplet generation

    As all capillaries from the RayDrop double emulsion device are easily exchangeable, users can change either the nozzle capillary or the collecting capillary with another nozzle or capillary size.

    It can also be tuned to target different droplet size by changing capillaries size and nozzle configuration:

    Small droplet configuration: 30µm-70µm-90µmThis two-nozzle configuration allows the device to decrease double emulsion size down to 50 µm.

    The versatility of the RayDrop double emulsion device allows for proper operation, independently of the wetting properties of the materials in contact with the fluids, and independently of the physicochemical properties of these fluids (interfacial tension, viscosity, density, miscibility). It additionally indicates that tuning the diameters of the nozzle tip and/or the extraction capillary enables it to cover a wide range of droplet diameters with any given fluid, a feature unachievable with other single devices.


    Device characteristicsCo-Flow focusing design
    Droplet typewater in oil in water and oil in water in oil
    Double emulsion sizeShell: 50 to 140 µm
    Core: 20 to 120 µm
    Generation rate5 000 Hz (measured for the smallest double emulsion size) – can go higher under specific conditions
    Nozzle typeMethalcrylate resin
    Nozzle sizeCore: 30 µm ID
    Shell: 70 µm ID
    Inlet and outlet capillary150 µm ID
    External dimensionsL*l*h = 92,5 mm * 52 mm * 13,5 mm
    Operating pressure0 – 5 bar
    Burst pressure10 bar
    Wetted material: continuous phasePEEK, FEP, glass, stainless steel, polyimide, Kalrez (seal), methalcrylate resin or glass (nozzle)
    Wetted laterial: dispersed phase PEEK, FEP, glass, methalcrylate resin or glass (nozzle)

    PNProduct nameCapillary sizesNozzle type
    ORDRPDE-30-70-150Complete Raydrop30µm-70µm-150µmMethacrylate Resin
    O-DE-RDRPC04-EUPComplete Raydrop30µm-70µm-90µmMethacrylate Resin
    O-SP-DNI3070-CODouble nozzle insert30µm-70µmMethacrylate Resin
    ORDRPSNO-90Simple nozzle insert90µmMethalcrylate resin
    ORDRPSNO-60Simple nozzle insert60µmMethacrylate Resin
    ORDRPCOL-150Collecting capillary insert150µmGlass

    Expertise & resources