Rate-limiting hydrodynamic resistance for controlled reagent delivery for laboratory solution preparation

The need for precise delivery of minute quantities of substances for solution preparation and other applications is well-known in research, clinical, industrial, and environmental settings. Currently available techniques for solution preparation in the laboratory include traditional transfer pipettes, micropipettes based on air displacement, and motorized devices using some form of a piston system. These techniques control the amount delivered by controlling the delivered volume. In this work we test the practicality of the concept of using a constant rate-limiting hydrodynamic resistance to achieve controlled reagent flow for solution preparation. The delivered amount is determined in this approach by time, pressure, flow resistance, or a combination of these. Good results are achieved comparable to conventional techniques without the use of fine mechanical instrumentation. This approach holds promise as an alternative to current methods of solution preparation and reagent delivery for routine laboratory use.