A viscometer array based on dynamic response of droplets driven by dielectric force

In this work, we present a novel viscometer array based on dynamic response of droplets driven by dielectric force. Each sensing element contains a small testing droplet (3 μL) sandwiched by upper and lower electrodes. When applying a bias voltage between the electrodes, the droplet changes its shape due to the dielectric force, causing capacitance change between the upper and lower electrodes. The viscosity of the droplet was measured from the time constant of the step response. The results show the sensing range of viscometer array is 10 cSt to 200 cSt less than 1000 ms.