Two-terminal longitudinal hotwire sensor for monitoring the position and speed of advancing liquid fronts in microfluidic channels

摘要

We report a simple and practical sensor for monitoring both the absolute position and advancing speed of liquid front in a microfluidic channel. The sensor consists of a longitudinal hot wire element—a two-terminal electrical device, with its length spanning the entire channel. The design, materials, fabrication method, and use of this sensor are extremely simple. Characterization results are presented.