Category: Automation and High-Throughput Technologies
While linear multichannel pipets enable many established assays, they do not support analytical tools with customized liquid holding geometries, specifically paper-based microfluidic devices. Existing tools for automated liquid handling, including robots and other commercial dispensers, are prohibitively expensive and highly specialized. Developers of paper diagnostics require volumetric tools that are modular, inexpensive, and ergonomic. We have developed a novel multichannel air displacement pipet with reconfigurable channels for customized, non-standard liquid handling applications. Using custom pipets, complex paper-based microfluidic devices can be fabricated without requiring multiple, time-consuming motions with a single-channel pipet or device designs limited to the configurations of traditional multichannel pipets. We created this tool by modifying a commercial 8-channel pipet using machined and 3D-printed components, and created pipets with unique 3, 4, 5, and 8-channel tip geometries to demonstrate our approach. We establish the quantitative capabilities of our tool by comparing its performance to that of a calibrated, single-channel pipet in volume delivery experiments. For our reconfigured three-channel pipet, the average accuracy and coefficient of variation for all channels were 98.1% and 4.9%, respectively. We used the two one-sided test to demonstrate that our reconfigured pipet is practically equivalent to a standard pipet within 5% of its nominal volume. This equivalence was maintained in paper-based glucose assays prepared using reconfigured and standard pipets. Our cost-effective reconfigurable pipet platform supports the advancement of custom analytical tools with non-standard liquid handling requirements and provides an ergonomic alternative to commercial equipment for developers of paper-based microfluidic devices.
Daniel Wilson– Graduate Student, Tufts University, Medford, MA
Daniel Wilson is a fourth year graduate student in the research group of Professor Charles R. Mace in the Department of Chemistry at Tufts University. He is a former recipient of a U.S. Department of Education GAANN fellowship. He graduated from the University of Rhode Island in 2014 with a B.A. in Chemistry and B.A. in Secondary Education. His research interests include instrument development, bioanalytical chemistry, low-cost diagnostics, and diagnostic device manufacturing.