Version 2.1 of the OpenDrop now features a feedback amplifier to detect droplet position and movement. The design is a simplified version of the amplifier used in the DropBot. First test measurements show that the amplifier detects presence of droplets also in the configuration of the OpenDrop device using a hydrophobic foil on top of the electrodes.

Measurement with droplet present under activated electrode. Upper line shows feedback signal from amplifier. With peak at the end of the switching periode.

Same measurement without a droplet, no peak.

Zooming into the peak.

Next task is to implement the position and motion detection into the code library.

A first test script shows the functionality