Development of a wirelessly-controlled electrolysis pump for automation of bioanalytical assays in Centrifugal Microfluidic Devices

Bioanalytical assays for diagnosis of infectious diseases are typically performed in sophisticated labs with highly trained technicians. Unfortunately, these labs are not accessible to everybody because the service is either expensive or far from the patients in unprivileged and remote areas. Reaching millions of people, particularly in the rural environment of developing countries needs more affordable technologies. Centrifugal Microfluidic Devices have been used to automate complex bioanalytical assays and the technology has reached good maturity. However, incorporation of other techniques to manipulate the fluid, aside from the centrifugal forces, will increase the applicability of the technology for “Point-of-Care” diagnosis. Particularly, the availability of small-footprint pumps able to supply specific amounts of fluid during the different assay steps will allow integration of much more complex assays in a single disc. Conveniently, recent electrification of centrifugal microfluidic devices has opened the possibility to incorporate electrical and electrochemical sensors and actuators to the discs, which can even be controlled wirelessly. This work presents the design and implementation of a wirelessly-controlled electrolysis pump for centrifugal microfluidics platforms. By applying an electrical current to water in a chamber, electrolysis and subsequence accumulation of gases create a pneumatic pressure that enables the supply of specific fluid volumes during the different stages of complex assays. As a proof of concept, a centrifugal microfluidic device with a series of electrolysis pumps has been developed to automate a peptides-microarray-based immunoassay for the detection of influenza Hemagglutinin (HA) proteins.