Experimental validation of a simple, low-cost, T-junction droplet generator fabricated through 3D printing

Abstract

Three-dimensional printing has been recently proposed and assessed for continuous flow microfluidic devices. In this paper the focus is on a new application of this rapid and low cost method for microfluidic device prototyping: droplets production through a T-junction generator. The feasibility of this new methodology is assessed by means of an experimental study in which the statistical parameters which characterize the production of droplets are analyzed. Furthermore, this study assesses the validity of previous theoretical and experimental results, obtained for a PDMS T-junction droplet generator, also in the case of a 3D printed Acrylonitrile microfluidic chip. Finally, the feasibility of producing monodisperse droplets by analyzing the polydispersity index of the prepared droplets is demonstrated.

3D printed fittings and fluidic modules for customizable droplet generators

“…Standardized needles were available with smaller inner diameters (60 mm) than the printable channel widths of the 3D printed device. [22][23][24][25] The use of standard needles with xed apertures also ensured the repeatability of fabrication. The diameters of the needles can be selected from 60 mm (34 G) to 1.4 mm (14 G).…”

“…Finally, it is difficult to alter the conguration of the device aer fabrication in a completely 3D printed device [22][23][24][25] as the channels are xed and there is no modiable component. In our approach, the modication of the assembled device was achieved for the geometry of the channels (with different 3D printed ttings) as well as the dimension of the nozzles (with different standardized needles).…”

“…Fabrication of such droplet generators has been demonstrated primarily in three different routes: (1) so lithography and replica molding [19][20][21] (2) 3D printing [22][23][24][25][26][27] and (3) manual assembly of uidic units. [28][29][30][31][32][33][34] So lithography employs photolithography followed by replica molding with polydimethylsiloxane (PDMS).…”

“…[35][36][37][38] Alternatively, the recent advance in 3D printing has allowed fabricating microuidic devices designed in computer-aided design (CAD) les. [22][23][24][25][26][27] In stereolithography and polymer jetting 3D printing, the evacuation of the uncured resin or the support materials to form narrow channels is oen challenging. [23][24][25]27 Multistep postprocessing to remove uncured resin 23 or support material 27 is oen required.…”

Moving from millifluidic to truly microfluidic sub-100-μm cross-section 3D printed devices

“…They found that removal of support material limited the minimum feature size that could be made. A droplet generator was made via PJ printing that could form different sizes of droplets; their theoretical and experimental sizes were compared, and the polydispersity index of the droplets was determined [40]. …”