OMIS – the Open Millifluidic Inquiry System

What is OMIS?

OMIS is a platform for exploring lab-on-a-chip technologies and miniaturized analysis systems.  It is a 3D printed, Arduino-based science and engineering project that allows the end-user (student/teacher/hobbyist) to explore the science of fluids.  The main features (at present) consist of a syringe pump constructed from 3D printed parts, an inexpensive stepper motor and some items from the local hardware store.  The second part is a “millifluidic device” which is also 3D printed.  OMIS is designed with learning and inquiry in mind, and all elements of the design have been created to encourage exploration.

What is the motivation for OMIS?

Miniaturized analysis systems (MAS) started to become available as early as the 90s.  is an emergent (not really, started in 90’s) field in science and engineering. Will MASs, one can learn much about the properties of mixtures (viscosity, diffusion coefficients), perform chemical reactions and measure properties such as pH and conductivity with very small sample volumes. Due perhaps to its complexity and more likely to its start-up costs, MAS is rarely integrated into the undergraduate curriculum.  I was searching for a solution to this pedagogical problem and it became clear that there was some room for innovation in the area of educational fluidic devices.  For me, a solution would incorporate these aspects:

  • uses low-cost, easily accessible components
  • has acceptable levels of complexity
  • built upon an inquiry-based platform

Truth be told, the main components of this project: an open-hardware syringe pump and 3D printed millifluidic systems, are not novel.  Plans for an open hardware syringe pump already exist and Lee Cronin at the University of Glasgow has demonstrated the versatility of 3D printed millifluidics in a number of papers.  My contributions to this area originated with the question, “The 5 V DC stepper motor from Adafruit is cheap, well documented and can be powered through a microcontroller; what’s the best performing syringe pump I can make with this motor?”  Trying to solve problems with limitations is a major component of scientific and engineering inquiry.  The other novel part of my project is the focus on education and exploration.  Making MAS accessible to high school and undergraduate science students is the primary objective of this project.

What can you do with OMIS?

OMIS is divided into three categories:

  • building it
  • controlling it
  • using it

While there is a significant amount of overlap between the three categories, I consider Building OMIS an engineering project, Controlling OMIS a computer science project and Using OMIS a Chemistry/Physics project.  I was inspired by a perspectives piece written by Ronald Breslow that identified “systems over substances” as a challenge for next-generation Chemistry.  OMIS is my attempt to introduce a systems-approach to problem solving into the high-school and undergraduate STEM curriculum.

OMIS is in the early stages of development and initial projects focus on the design of a functioning system (device fabrication, control and optimization).  A proof-of-concept millifluidic device demonstrates an important concept in MAS – laminar flow – and how flow rate influences the mixing of two fluid streams in a single channel.

As OMIS matures, so will the body of projects and explorations utilizing the system.  In both the hardware and software design, significant efforts have been made to incorporate modular and parametric strategies so that end-users can customize the system as they see fit.  Want to use different syringes?  Just change one variable and reprint.  Want a single-bore instead of a dual-bore syringe pump?  Done with the change of one line of code.  Don’t like PCs or want to operate your system from a Raspberry Pi?  Serial communication makes that possible.

Where should I begin?

OMIS is found in three places:

  • Here, at my website.  I’ll use this area for more commentary and sharing of my thoughts (periodically).
  • I’ll use Github for the current release of the designs, software and documentation.  It is perhaps a non-traditional use for Github; however I think the ability to easily publish releases and track issues will be beneficial.
  • Thingiverse is where the original design is posted, and I hope that users will visit there to like/comment/critique or do whatever level of social media you like to do.

Listed below is the set of pages on my website that are related to OMIS.