- Why is this chip not working?
- Is this what this chip should be doing right now?
- What part of this chip is failing?
The common theme underlying these questions was our inability to explain why our microfluidics chips were not functioning correctly. When we had performed a literature review there were no papers published regarding a standardized method of evaluating microfluidic chips. With that problem in mind the team went on to create an evaluation system known as Fluid Functionality.
Fluid Functionality is based around analyzing the functionality of each primitive in a microfluidic chip (refer to Microfluidics 101 on our Wiki for more information regarding primitives.) These primitives can be thought of as the individual electrical components that are a part of a larger circuit. If one and/or more primitive malfunctions the entire system will not work. However, how do we go about analyzing each primitive? Primitive analysis can be broken up into two parts:
- Qualitative: Observations that provide any indication of failure.
- Quantitative: Calculations that show whether your primitive failed or not.
By inter-relating the qualitative failures we have observed with a corresponding quantitative analysis method we can explain why a microfluidic chip is not working. If, for example, a primitive has a qualitative failure and fails its quantitative test, then there is something wrong with the primitive's dimensions. But if a primitive has a qualitative failure and passes its quantitative test, then there is some other source of error such as poor assembly. At this time these relationships are not fully defined. More work in the future can yield a better relationship between which qualitative failure pairs with quantitative test. Fluid Functionality can primarily be utilized as a modeling framework.
iGEM has done an excellent job of defining modeling projects related to wet lab experiments, however since MARS is a hardware project this was our team’s approach of modeling our work. The sections below describe the qualitative and quantitative analyses we have developed.