(777h) 3D Printed Active Microfluidic Elements for Portable Bioanalysis Assays

There is an ongoing need for simple, inexpensive, and robust systems that replicate functions of conventional bioanalysis instruments in a format with sufficient portability to deploy in resource-limited settings. A key challenge in the development of these systems, however, involves the ability to dispense precisely metered quantities of liquid reagents and drive their transport through microfluidic networks. Active mechanical pumps offer considerable flexibility compared with passive methods (e.g., capillary wicking in paper-based systems), but sacrifice operational complexity electrical power consumption. Here we describe a novel approach to overcome these limitations by leveraging shape memory polymers to construct a library of fluidic control elements that can be assembled in various arrangements to execute sequential fluidic operations associated with field-based diagnostic assays. These elements (pumps, valves) are easily produced using conventional 3D printing technology, and display a shape memory response within a temperature range that allows them to be operated by exposure to heated water, eliminating the need for battery power and permitting operation by personnel with minimal training.