Development of on-chip sensing technologies for applications in Microfluidics

The size of a typical microfluidic device is 2 cm X 2 cm or smaller. Microfluidics lab-on-a-chip and point-of-care applications involve miniaturization of laboratory systems to accomplish tasks on-chip. We aim to develop sensors that can be integrated on-chip at the desired location for real-time measurement of fluid and flow parameters.

In our research work, we have developed electrochemical flow sensors for electrolytic fluids that can measure flow rates in the range 0-500 µL/min with flow resolution of 1 µL/min. We also observed that the electrochemical flow sensor based on resistance of electrolytically generated gas bubbles has a high sensitivity to most fluid flow parameters including pressure, temperature, and viscosity; thus, presenting an opportunity to measure multiple parameters using a single sensor.

We have also developed flow sensors based on chronoamperometry, using chronoamperograms to characterize fluid flow. The sensor has a range of 0-200 µL/min with resolution ≈ 10 µL/min. Sensors are an essential component of all fluid systems, both at macro and micro scales. With the ability to integrate flow sensors, we move one step closer to integrating mechanical systems for independent operation of a microfluidic chip.