Date of Graduation


Document Type


Degree Name

Bachelor of Science in Mechanical Engineering

Degree Level



Mechanical Engineering


Tung, Steve

Committee Member/Reader

Couvillion, Rick

Committee Member/Second Reader

Roe, Larry


This paper details an investigation into methods and designs of 3D printing a microfluidic system capable of droplet emulsion using NinjaFlex filament. The specific field in which this paper’s experiment is rooted is dubbed “BioMEMS,” short for bio microelectromechanical systems. One prominent research area in BioMEMS is developing a “lab on a chip.” Essentially, the goal is to miniaturize common lab processes to the micro scale, rendering it possible to include these processes in a small chip. Reducing necessary sample sizes, shortening the reaction times of lab processes, and increasing mobility of lab processes can all be realized through microfluidic designs.

This experiment specifically investigates the ways in which micro droplets can be generated in a chip 3D printed from NinjaFlex filament. Printing in NinjaFlex came with a few challenges, including blocked micro channels from unintentionally extruded material and an unreliable bond with glass. However, at a set of optimum print parameters and utilizing a specially tailored design, it was found that NinjaFlex could reliably be used to 3D print a microfluidic system capable of droplet emulsion. For the final design iteration described in this paper, a oil side pressure of 2.5 psig and a water side flow rate of 25 microliters/minute induced uniformly sized droplets (about 1100 microns in diameter) at a regular time interval of about one every four seconds. In future research, it would be useful to have more control over the oil side flow rate. Also, there is room to optimize the current chip design by adding flexible diaphragms or reducing the diameter of the micro channels, thus giving the user more control over the droplet size and interval of formation.


microfluidics, droplets, 3D printing, BioMEMS, NinjaFlex, MakerBot